# The Mutt E-Mail Client

### Michael Elkins

`<me@cs.hmc.edu>`

version 1.5.19 (2009-01-05)

Abstract

“All mail clients suck. This one just sucks less.” -me, circa 1995

List of Tables

1.1. Typographical conventions for special terms
2.1. Most common navigation keys
2.2. Most common line editor keys
2.3. Most common message index keys
2.4. Message status flags
2.5. Message recipient flags
2.6. Most common pager keys
2.7. ANSI escape sequences
2.8. Color sequences
2.9. Most common thread mode keys
2.10. Most common mail sending keys
2.11. Most common compose menu keys
2.12. PGP key menu flags
3.1. Symbolic key names
4.1. POSIX regular expression character classes
4.2. Regular expression repetition operators
4.3. GNU regular expression extensions
4.4. Pattern modifiers
4.5. Simple search keywords
4.6. Date units
8.1. Command line options

List of Examples

3.1. Multiple configuration commands per line
3.2. Commenting configuration files
3.3. Escaping quotes in congfiguration files
3.4. Using external command's output in configuration files
3.5. Using environment variables in configuration files
3.6. Configuring external alias files
3.7. Setting sort method based on mailbox name
3.8. Header weeding
3.9. Configuring header display order
3.10. Defining custom headers
3.11. Using %-expandos in `save-hook`
3.12. Embedding `push` in `folder-hook`
3.13. Configuring spam detection
3.14. Using user-defined variables for config file readability
3.15. Using user-defined variables for backing up other config option values
3.16. Deferring user-defined variable expansion to runtime
3.17. Using external filters in format strings
4.1. Using boolean operators in patterns
4.2. Combining `send-hook` and `my_hdr`
5.1. Attachment counting

## Chapter 1. Introduction

Mutt is a small but very powerful text-based MIME mail client. Mutt is highly configurable, and is well suited to the mail power user with advanced features like key bindings, keyboard macros, mail threading, regular expression searches and a powerful pattern matching language for selecting groups of messages.

## 1. Mutt Home Page

The official homepage can be found at http://www.mutt.org/.

## 2. Mailing Lists

To subscribe to one of the following mailing lists, send a message with the word subscribe in the body to `list-name`-request`@mutt.org`.

- `<mutt-announce-request@mutt.org>` -- low traffic list for announcements

- `<mutt-users-request@mutt.org>` -- help, bug reports and feature requests

- `<mutt-dev-request@mutt.org>` -- development mailing list

### Note

All messages posted to mutt-announce are automatically forwarded to mutt-users, so you do not need to be subscribed to both lists.

## 3. Software Distribution Sites

Mutt releases can be downloaded from ftp://ftp.mutt.org/mutt/. For a list of mirror sites, please refer to http://www.mutt.org/download.html.

## 4. Mutt online resources

Bug Tracking System

  The official mutt bug tracking system can be found at http://dev.mutt.org/

Wiki

  An (unofficial) wiki can be found at http://wiki.mutt.org/.

IRC

  For the IRC user community, visit channel #mutt on irc.freenode.net.

USENET

  For USENET, see the newsgroup comp.mail.mutt.

## 5. Contributing to Mutt

There are various ways to contribute to the Mutt project.

Especially for new users it may be helpful to meet other new and experienced users to chat about Mutt, talk about problems and share tricks.

Since translations of Mutt into other languages are highly appreciated, the mutt developers always look for skilled translators that help improve and continue to maintain stale translations.

For contributing code patches for new features and bug fixes, please refer to the developer pages at http://dev.mutt.org/ for more details.

## 6. Typograhical conventions

This section lists typographical conventions followed throughout this manual. See table Table 1.1, “Typographical conventions for special terms” for typographical conventions for special terms.

Table 1.1. Typographical conventions for special terms

Item | Refers to...
--- | ---
`printf(3)` | UNIX manual pages, execute `man 3 printf`
`<PageUp>` | named keys
`<create-alias>` | named Mutt function
`^G` | Control+G key combination
`$mail_check` | Mutt configuration option

Examples are presented as:

    mutt -v

Within command synopsis, curly brackets (“{}”) denote a set of options of which one is mandatory, square brackets (“[]”) denote optional arguments, three dots denote that the argument may be repeated arbitrary times.

## 7. Copyright

Mutt is Copyright (C) 1996-2009 Michael R. Elkins `<me@mutt.org>` and others.

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.

## Chapter 2. Getting Started

This section is intended as a brief overview of how to use Mutt. There are many other features which are described elsewhere in the manual. There is even more information available in the Mutt FAQ and various web pages. See the Mutt homepage for more details.

The keybindings described in this section are the defaults as distributed. Your local system administrator may have altered the defaults for your site. You can always type “?” in any menu to display the current bindings.

The first thing you need to do is invoke mutt, simply by typing `mutt` at the command line. There are various command-line options, see either the mutt man page or the reference.

## 1. Core concepts

Mutt is a text-based application which interacts with users through different menus which are mostly line-/entry-based or page-based. A line-based menu is the so-called “index” menu (listing all messages of the currently opened folder) or the “alias” menu (allowing you to select recipients from a list). Examples for page-based menus are the “pager” (showing one message at a time) or the “help” menu listing all available key bindings.

The user interface consists of a context sensitive help line at the top, the menu's contents followed by a context sensitive status line and finally the command line. The command line is used to display informational and error messages as well as for prompts and for entering interactive commands.

Because Mutt allows for customizing almost all key bindings, there are so-called “functions” which can be executed manually (using the command line) or in macros. Macros allow the user to bind a sequence of commands to a single key or a short key sequence instead of repeating a sequence of actions over and over.

Many commands (such as saving or copying a message to another folder) can be applied to a single message or a set of messages (so-called “tagged” messages). To help selecting messages, Mutt provides a rich set of message patterns (such as recipients, sender, body contents, date sent/received, etc.) which can be combined into complex expressions using the boolean and and or operations as well as negating. These patterns can also be used to (for example) search for messages or to limit the index to show only matching messages.

Mutt supports a “hook” concept which allows the user to execute arbitrary configuration commands and functions in certain situations such as entering a folder, starting a new message or replying to an existing one. These hooks can be used to highly customize Mutt's behaviour including managing multiple identities, customizing the display for a folder or even implementing auto-archiving based on a per-folder basis and much more.

## 2. Moving Around in Menus

The most important navigation keys common to all menus are shown in Table 2.1, “Most common navigation keys”.

Table 2.1. Most common navigation keys

Key | Function | Description
--- | --- | ---
j or <Down> | `<next-entry>` | move to the next entry
k or <Up> | `<previous-entry>` | move to the previous entry
z or <PageDn> | `<page-down>` | go to the next page
Z or <PageUp> | `<page-up>` | go to the previous page
= or <Home> | `<first-entry>` | jump to the first entry
* or <End> | `<last-entry>` | jump to the last entry
q | `<quit>` | exit the current menu
? | `<help>` | list all keybindings for the current menu

## 3. Editing Input Fields

### 3.1. Introduction

Mutt has a built-in line editor for inputting text, e.g. email addresses or filenames. The keys used to manipulate text input are very similar to those of Emacs. See Table 2.2, “Most common line editor keys” for a full reference of available functions, their default key bindings, and short descriptions.

Table 2.2. Most common line editor keys

Key | Function | Description
--- | --- | ---
^A or <Home> | `<bol>` | move to the start of the line
^B or <Left> | `<backward-char>` | move back one char
Esc B | `<backward-word>` | move back one word
^D or <Delete> | `<delete-char>` | delete the char under the cursor
^E or <End> | `<eol>` | move to the end of the line
^F or <Right> | `<forward-char>` | move forward one char
Esc F | `<forward-word>` | move forward one word
<Tab> | `<complete>` | complete filename or alias
^T | `<complete-query>` | complete address with query
^K | `<kill-eol>` | delete to the end of the line
Esc d | `<kill-eow>` | delete to the end of the word
^W | `<kill-word>` | kill the word in front of the cursor
^U | `<kill-line>` | delete entire line
^V | `<quote-char>` | quote the next typed key
<Up> | `<history-up>` | recall previous string from history
<Down> | `<history-down>` | recall next string from history
<BackSpace> | `<backspace>` | kill the char in front of the cursor
Esc u | `<upcase-word>` | convert word to upper case
Esc l | `<downcase-word>` | convert word to lower case
Esc c | `<capitalize-word>` | capitalize the word
^G | n/a | abort
<Return> | n/a | finish editing

You can remap the editor functions using the bind command. For example, to make the <Delete> key delete the character in front of the cursor rather than under, you could use:

    bind editor <delete> backspace

### 3.2. History

Mutt maintains a history for the built-in editor. The number of items is controlled by the $history variable and can be made persistent using an external file specified using $history_file. You may cycle through them at an editor prompt by using the `<history-up>` and/or `<history-down>` commands.

Mutt maintains several distinct history lists, one for each of the following categories:

- muttrc commands

- addresses and aliases

- shell commands

- filenames

- patterns

- everything else

Mutt automatically filters out repeated items from the history. It also mimics the behavior of some shells by ignoring items starting with a space. The latter feature can be useful in macros to not clobber the history's valuable entries with unwanted entries.

## 4. Reading Mail - The Index and Pager

Similar to many other mail clients, there are two modes in which mail is read in Mutt. The first is the index of messages in the mailbox, which is called the “index” in Mutt. The second mode is the display of the message contents. This is called the “pager.”

The next few sections describe the functions provided in each of these modes.

### 4.1. The Message Index

Common keys used to navigate through and manage messages in the index are shown in Table 2.3, “Most common message index keys”. How messages are presented in the index menu can be customized using the $index_format variable.

Table 2.3. Most common message index keys

Key | Description
--- | ---
c | change to a different mailbox
Esc c | change to a folder in read-only mode
C | copy the current message to another mailbox
Esc C | decode a message and copy it to a folder
Esc s | decode a message and save it to a folder
D | delete messages matching a pattern
d | delete the current message
F | mark as important
l | show messages matching a pattern
N | mark message as new
o | change the current sort method
O | reverse sort the mailbox
q | save changes and exit
s | save-message
T | tag messages matching a pattern
t | toggle the tag on a message
Esc t | toggle tag on entire message thread
U | undelete messages matching a pattern
u | undelete-message
v | view-attachments
x | abort changes and exit
<Return> | display-message
<Tab> | jump to the next new or unread message
@ | show the author's full e-mail address
$ | save changes to mailbox
/ | search
Esc / | search-reverse
^L | clear and redraw the screen
^T | untag messages matching a pattern

In addition to who sent the message and the subject, a short summary of the disposition of each message is printed beside the message number. Zero or more of the “flags” in Table 2.4, “Message status flags” may appear, some of which can be turned on or off using these functions: `<set-flag>` and `<clear-flag>` bound by default to “w” and “W” respectively.

Furthermore, the flags in Table 2.5, “Message recipient flags” reflect who the message is addressed to. They can be customized with the $to_chars variable.

Table 2.4. Message status flags

Flag | Description
--- | ---
D | message is deleted (is marked for deletion)
d | message has attachments marked for deletion
K | contains a PGP public key
N | message is new
O | message is old
P | message is PGP encrypted
r | message has been replied to
S | message is signed, and the signature is successfully verified
s | message is signed
! | message is flagged
* | message is tagged

Table 2.5. Message recipient flags

Flag | Description
--- | ---
+ | message is to you and you only
T | message is to you, but also to or cc'ed to others
C | message is cc'ed to you
F | message is from you
L | message is sent to a subscribed mailing list

### 4.2. The Pager

By default, Mutt uses its builtin pager to display the contents of messages. The pager is very similar to the Unix program less though not nearly as featureful.

Table 2.6. Most common pager keys

Key | Description
--- | ---
<Return> | go down one line
<Space> | display the next page (or next message if at the end of a message)
- | go back to the previous page
n | search for next match
S | skip beyond quoted text
T | toggle display of quoted text
? | show keybindings
/ | regular expression search
Esc / | backward regular expression search
\ | toggle highlighting of search matches
^ | jump to the top of the message

In addition to key bindings in Table 2.6, “Most common pager keys”, many of the functions from the index menu are also available in the pager, such as `<delete-message>` or `<copy-message>` (this is one advantage over using an external pager to view messages).

Also, the internal pager supports a couple other advanced features. For one, it will accept and translate the “standard” nroff sequences for bold and underline. These sequences are a series of either the letter, backspace (^H), the letter again for bold or the letter, backspace, “_” for denoting underline. Mutt will attempt to display these in bold and underline respectively if your terminal supports them. If not, you can use the bold and underline color objects to specify a color or mono attribute for them.

Additionally, the internal pager supports the ANSI escape sequences for character attributes. Mutt translates them into the correct color and character settings. The sequences Mutt supports are:

    \e[Ps;Ps;..Ps;m

where Ps can be one of the codes shown in Table 2.7, “ANSI escape sequences”.

Table 2.7. ANSI escape sequences

Escape code | Description
--- | ---
0 | All attributes off
1 | Bold on
4 | Underline on
5 | Blink on
7 | Reverse video on
3<color> | Foreground color is <color> (see Table 2.8, “Color sequences”)
4<color> | Background color is <color> (see Table 2.8, “Color sequences”)

Table 2.8. Color sequences

Color code | Color
--- | ---
0 | Black
1 | Red
2 | Green
3 | Yellow
4 | Blue
5 | Magenta
6 | Cyan
7 | White

Mutt uses these attributes for handling `text/enriched` messages, and they can also be used by an external autoview script for highlighting purposes.

### Note

If you change the colors for your display, for example by changing the color associated with color2 for your xterm, then that color will be used instead of green.

### Note

Note that the search commands in the pager take regular expressions, which are not quite the same as the more complex patterns used by the search command in the index. This is because the pager only performs simple text search, whereas the index provides boolean filtering on several aspects of messages.

### 4.3. Threaded Mode

When the mailbox is sorted by threads, there are a few additional functions available in the index and pager modes as shown in Table 2.9, “Most common thread mode keys”.

Table 2.9. Most common thread mode keys

Key | Function | Description
--- | --- | ---
^D | `<delete-thread>` | delete all messages in the current thread
^U | `<undelete-thread>` | undelete all messages in the current thread
^N | `<next-thread>` | jump to the start of the next thread
^P | `<previous-thread>` | jump to the start of the previous thread
^R | `<read-thread>` | mark the current thread as read
Esc d | `<delete-subthread>` | delete all messages in the current subthread
Esc u | `<undelete-subthread>` | undelete all messages in the current subthread
Esc n | `<next-subthread>` | jump to the start of the next subthread
Esc p | `<previous-subthread>` | jump to the start of the previous subthread
Esc r | `<read-subthread>` | mark the current subthread as read
Esc t | `<tag-thread>` | toggle the tag on the current thread
Esc v | `<collapse-thread>` | toggle collapse for the current thread
Esc V | `<collapse-all>` | toggle collapse for all threads
P | `<parent-message>` | jump to parent message in thread

### Note

Collapsing a thread displays only the first message in the thread and hides the others. This is useful when threads contain so many messages that you can only see a handful of threads on the screen. See %M in $index_format. For example, you could use "%?M?(#%03M)&(%4l)?" in $index_format to optionally display the number of hidden messages if the thread is collapsed.

See also: $strict_threads.

### 4.4. Miscellaneous Functions

In addition, the index and pager menus have these interesting functions:

`<create-alias>` (default: a)

  Creates a new alias based upon the current message (or prompts for a new one). Once editing is complete, an alias command is added to the file specified by the $alias_file variable for future use

  ### Note

  Mutt does not read the $alias_file upon startup so you must explicitly source the file.

`<check-traditional-pgp>` (default: Esc P)

  This function will search the current message for content signed or encrypted with PGP the “traditional” way, that is, without proper MIME tagging. Technically, this function will temporarily change the MIME content types of the body parts containing PGP data; this is similar to the `<edit-type>` function's effect.

`<edit>` (default: e)

  This command (available in the index and pager) allows you to edit the raw current message as it's present in the mail folder. After you have finished editing, the changed message will be appended to the current folder, and the original message will be marked for deletion; if the message is unchanged it won't be replaced.

`<edit-type>` (default: ^E on the attachment menu, and in the pager and index menus; ^T on the compose menu)

  This command is used to temporarily edit an attachment's content type to fix, for instance, bogus character set parameters. When invoked from the index or from the pager, you'll have the opportunity to edit the top-level attachment's content type. On the attachment menu, you can change any attachment's content type. These changes are not persistent, and get lost upon changing folders.

  Note that this command is also available on the compose menu. There, it's used to fine-tune the properties of attachments you are going to send.

`<enter-command>` (default: “:”)

  This command is used to execute any command you would normally put in a configuration file. A common use is to check the settings of variables, or in conjunction with macros to change settings on the fly.

`<extract-keys>` (default: ^K)

  This command extracts PGP public keys from the current or tagged message(s) and adds them to your PGP public key ring.

`<forget-passphrase>` (default: ^F)

  This command wipes the passphrase(s) from memory. It is useful, if you misspelled the passphrase.

`<list-reply>` (default: L)

  Reply to the current or tagged message(s) by extracting any addresses which match the regular expressions given by the lists or subscribe commands, but also honor any `Mail-Followup-To` header(s) if the $honor_followup_to configuration variable is set. Using this when replying to messages posted to mailing lists helps avoid duplicate copies being sent to the author of the message you are replying to.

`<pipe-message>` (default: |)

  Asks for an external Unix command and pipes the current or tagged message(s) to it. The variables $pipe_decode, $pipe_split, $pipe_sep and $wait_key control the exact behavior of this function.

`<resend-message>` (default: Esc e)

  Mutt takes the current message as a template for a new message. This function is best described as "recall from arbitrary folders". It can conveniently be used to forward MIME messages while preserving the original mail structure. Note that the amount of headers included here depends on the value of the $weed variable.

  This function is also available from the attachment menu. You can use this to easily resend a message which was included with a bounce message as a `message/rfc822` body part.

`<shell-escape>` (default: !)

  Asks for an external Unix command and executes it. The $wait_key can be used to control whether Mutt will wait for a key to be pressed when the command returns (presumably to let the user read the output of the command), based on the return status of the named command. If no command is given, an interactive shell is executed.

`<toggle-quoted>` (default: T)

  The pager uses the $quote_regexp variable to detect quoted text when displaying the body of the message. This function toggles the display of the quoted material in the message. It is particularly useful when being interested in just the response and there is a large amount of quoted text in the way.

`<skip-quoted>` (default: S)

  This function will go to the next line of non-quoted text which comes after a line of quoted text in the internal pager.

## 5. Sending Mail

### 5.1. Introduction

The bindings shown in Table 2.10, “Most common mail sending keys” are available in the index and pager to start a new message.

Table 2.10. Most common mail sending keys

Key | Function | Description
--- | --- | ---
m | `<compose>` | compose a new message
r | `<reply>` | reply to sender
g | `<group-reply>` | reply to all recipients
L | `<list-reply>` | reply to mailing list address
f | `<forward>` | forward message
b | `<bounce>` | bounce (remail) message
Esc k | `<mail-key>` | mail a PGP public key to someone

Bouncing a message sends the message as-is to the recipient you specify. Forwarding a message allows you to add comments or modify the message you are forwarding. These items are discussed in greater detail in the next chapter “Forwarding and Bouncing Mail.”

Mutt will then enter the compose menu and prompt you for the recipients to place on the “To:” header field. Next, it will ask you for the “Subject:” field for the message, providing a default if you are replying to or forwarding a message. See also $askcc, $askbcc, $autoedit, $bounce, $fast_reply, and $include for changing how Mutt asks these questions.

Mutt will then automatically start your $editor on the message body. If the $edit_headers variable is set, the headers will be at the top of the message in your editor. Any messages you are replying to will be added in sort order to the message, with appropriate $attribution, $indent_string and $post_indent_string. When forwarding a message, if the $mime_forward variable is unset, a copy of the forwarded message will be included. If you have specified a $signature, it will be appended to the message.

Once you have finished editing the body of your mail message, you are returned to the compose menu providing the functions shown in Table 2.11, “Most common compose menu keys” to modify, send or postpone the message.

Table 2.11. Most common compose menu keys

Key | Function | Description
--- | --- | ---
a | `<attach-file>` | attach a file
A | `<attach-message>` | attach message(s) to the message
Esc k | `<attach-key>` | attach a PGP public key
d | `<edit-description>` | edit description on attachment
D | `<detach-file>` | detach a file
t | `<edit-to>` | edit the To field
Esc f | `<edit-from>` | edit the From field
r | `<edit-reply-to>` | edit the Reply-To field
c | `<edit-cc>` | edit the Cc field
b | `<edit-bcc>` | edit the Bcc field
y | `<send-message>` | send the message
s | `<edit-subject>` | edit the Subject
S | `<smime-menu>` | select S/MIME options
f | `<edit-fcc>` | specify an “Fcc” mailbox
p | `<pgp-menu>` | select PGP options
P | `<postpone-message>` | postpone this message until later
q | `<quit>` | quit (abort) sending the message
w | `<write-fcc>` | write the message to a folder
i | `<ispell>` | check spelling (if available on your system)
^F | `<forget-passphrase>` | wipe passphrase(s) from memory

The compose menu is also used to edit the attachments for a message which can be either files or other messages. The `<attach-message>` function to will prompt you for a folder to attach messages from. You can now tag messages in that folder and they will be attached to the message you are sending.

### Note

Note that certain operations like composing a new mail, replying, forwarding, etc. are not permitted when you are in that folder. The %r in $status_format will change to a “A” to indicate that you are in attach-message mode.

### 5.2. Editing the message header

When editing the header because of $edit_headers being set, there are a several pseudo headers available which will not be included in sent messages.

#### 5.2.1. Fcc: pseudo header

If you specify `Fcc:` filename as a header, Mutt will pick up filename just as if you had used the `<edit-fcc>` function in the compose menu.

#### 5.2.2. Attach: pseudo header

You can also attach files to your message by specifying `Attach:` filename [ description ] where filename is the file to attach and description is an optional string to use as the description of the attached file.

#### 5.2.3. Pgp: pseudo header

If you want to use PGP, you can specify

`Pgp:` [ `E` | `S` | `S`<id> ]

“E” selects encryption, “S” selects signing and “S<id>” selects signing with the given key, setting $pgp_sign_as permanently.

#### 5.2.4. In-Reply-To: header

When replying to messages, the In-Reply-To: header contains the Message-Id of the message(s) you reply to. If you remove its value, Mutt will not generate a References: field, which allows you to create a new message thread, for example to create a new message to a mailing list without having to enter the mailing list's address.

### 5.3. Sending cryptographically signed/encrypted messages

If you have told mutt to PGP or S/MIME encrypt a message, it will guide you through a key selection process when you try to send the message. Mutt will not ask you any questions about keys which have a certified user ID matching one of the message recipients' mail addresses. However, there may be situations in which there are several keys, weakly certified user ID fields, or where no matching keys can be found.

In these cases, you are dropped into a menu with a list of keys from which you can select one. When you quit this menu, or mutt can't find any matching keys, you are prompted for a user ID. You can, as usually, abort this prompt using `^G`. When you do so, mutt will return to the compose screen.

Once you have successfully finished the key selection, the message will be encrypted using the selected public keys when sent out.

Most fields of the entries in the key selection menu (see also $pgp_entry_format) have obvious meanings. But some explanations on the capabilities, flags, and validity fields are in order.

The flags sequence (%f) will expand to one of the flags in Table 2.12, “PGP key menu flags”.

Table 2.12. PGP key menu flags

Flag | Description
--- | ---
R | The key has been revoked and can't be used.
X | The key is expired and can't be used.
d | You have marked the key as disabled.
c | There are unknown critical self-signature packets.

The capabilities field (%c) expands to a two-character sequence representing a key's capabilities. The first character gives the key's encryption capabilities: A minus sign (“-”) means that the key cannot be used for encryption. A dot (“.”) means that it's marked as a signature key in one of the user IDs, but may also be used for encryption. The letter “e” indicates that this key can be used for encryption.

The second character indicates the key's signing capabilities. Once again, a “-” implies “not for signing”, “.” implies that the key is marked as an encryption key in one of the user-ids, and “s” denotes a key which can be used for signing.

Finally, the validity field (%t) indicates how well-certified a user-id is. A question mark (“?”) indicates undefined validity, a minus character (“-”) marks an untrusted association, a space character means a partially trusted association, and a plus character (“+”) indicates complete validity.

### 5.4. Sending anonymous messages via mixmaster

You may also have compiled mutt to co-operate with Mixmaster, an anonymous remailer. Mixmaster permits you to send your messages anonymously using a chain of remailers. Mixmaster support in mutt is for mixmaster version 2.04 (beta 45 appears to be the latest) and 2.03. It does not support earlier versions or the later so-called version 3 betas, of which the latest appears to be called 2.9b23.

To use it, you'll have to obey certain restrictions. Most important, you cannot use the `Cc` and `Bcc` headers. To tell Mutt to use mixmaster, you have to select a remailer chain, using the mix function on the compose menu.

The chain selection screen is divided into two parts. In the (larger) upper part, you get a list of remailers you may use. In the lower part, you see the currently selected chain of remailers.

You can navigate in the chain using the `<chain-prev>` and `<chain-next>` functions, which are by default bound to the left and right arrows and to the `h` and `l` keys (think vi keyboard bindings). To insert a remailer at the current chain position, use the `<insert>` function. To append a remailer behind the current chain position, use `<select-entry>` or `<append>`. You can also delete entries from the chain, using the corresponding function. Finally, to abandon your changes, leave the menu, or `<accept>` them pressing (by default) the `Return` key.

Note that different remailers do have different capabilities, indicated in the %c entry of the remailer menu lines (see $mix_entry_format). Most important is the “middleman” capability, indicated by a capital “M”: This means that the remailer in question cannot be used as the final element of a chain, but will only forward messages to other mixmaster remailers. For details on the other capabilities, please have a look at the mixmaster documentation.

### 5.5. Sending format=flowed messages

#### 5.5.1. Concept

`format=flowed`-style messages (or `f=f` for short) are `text/plain` messages that consist of paragraphs which a receiver's mail client may reformat to its own needs which mostly means to customize line lengths regardless of what the sender sent. Technically this is achieved by letting lines of a “flowable” paragraph end in spaces except for the last line.

While for text-mode clients like mutt it's the best way to assume only a standard 80x25 character cell terminal, it may be desired to let the receiver decide completely how to view a message.

#### 5.5.2. Mutt support

Mutt only supports setting the required `format=flowed` MIME parameter on outgoing messages if the $text_flowed variable is set, specifically it does not add the trailing spaces.

After editing the initial message text and before entering the compose menu, mutt properly space-stuffes the message. Space-stuffing is required by RfC3676 defining `format=flowed` and means to prepend a space to:

- all lines starting with a space

- lines starting with the word “`From`” followed by space

- all lines starting with “`>`” which is not intended to be a quote character

### Note

Mutt only supports space-stuffing for the first two types of lines but not for the third: It is impossible to safely detect whether a leading `>` character starts a quote or not. Furthermore, Mutt only applies space-stuffing once after the initial edit is finished.

All leading spaces are to be removed by receiving clients to restore the original message prior to further processing.

#### 5.5.3. Editor considerations

As mutt provides no additional features to compose `f=f` messages, it's completely up to the user and his editor to produce proper messages. Please consider your editor's documentation if you intend to send `f=f` messages.

Please note that when editing messages from the compose menu several times before really sending a mail, it's up to the user to ensure that the message is properly space-stuffed.

For example, vim provides the `w` flag for its `formatoptions` setting to assist in creating `f=f` messages, see `:help fo-table` for details.

## 6. Forwarding and Bouncing Mail

Bouncing and forwarding let you send an existing message to recipients that you specify. Bouncing a message sends a verbatim copy of a message to alternative addresses as if they were the message's original recipients specified in the Bcc header. Forwarding a message, on the other hand, allows you to modify the message before it is resent (for example, by adding your own comments). Bouncing is done using the `<bounce>` function and forwarding using the `<forward>` function bound to “b” and “f” respectively.

Forwarding can be done by including the original message in the new message's body (surrounded by indicating lines) or including it as a MIME attachment, depending on the value of the $mime_forward variable. Decoding of attachments, like in the pager, can be controlled by the $forward_decode and $mime_forward_decode variables, respectively. The desired forwarding format may depend on the content, therefore $mime_forward is a quadoption which, for example, can be set to “ask-no”.

The inclusion of headers is controlled by the current setting of the $weed variable, unless $mime_forward is set.

Editing the message to forward follows the same procedure as sending or replying to a message does.

## 7. Postponing Mail

At times it is desirable to delay sending a message that you have already begun to compose. When the `<postpone-message>` function is used in the compose menu, the body of your message and attachments are stored in the mailbox specified by the $postponed variable. This means that you can recall the message even if you exit Mutt and then restart it at a later time.

Once a message is postponed, there are several ways to resume it. From the command line you can use the “-p” option, or if you compose a new message from the index or pager you will be prompted if postponed messages exist. If multiple messages are currently postponed, the postponed menu will pop up and you can select which message you would like to resume.

### Note

If you postpone a reply to a message, the reply setting of the message is only updated when you actually finish the message and send it. Also, you must be in the same folder with the message you replied to for the status of the message to be updated.

See also the $postpone quad-option.

## Chapter 3. Configuration

## 1. Location of initialization files

While the default configuration (or “preferences”) make Mutt usable right out of the box, it is often desirable to tailor Mutt to suit your own tastes. When Mutt is first invoked, it will attempt to read the “system” configuration file (defaults set by your local system administrator), unless the “-n” command line option is specified. This file is typically `/usr/local/share/mutt/Muttrc` or `/etc/Muttrc`. Mutt will next look for a file named `.muttrc` in your home directory. If this file does not exist and your home directory has a subdirectory named `.mutt`, mutt try to load a file named `.mutt/muttrc`.

`.muttrc` is the file where you will usually place your commands to configure Mutt.

In addition, mutt supports version specific configuration files that are parsed instead of the default files as explained above. For instance, if your system has a `Muttrc-0.88` file in the system configuration directory, and you are running version 0.88 of mutt, this file will be sourced instead of the `Muttrc` file. The same is true of the user configuration file, if you have a file `.muttrc-0.88.6` in your home directory, when you run mutt version 0.88.6, it will source this file instead of the default `.muttrc` file. The version number is the same which is visible using the “-v” command line switch or using the `show-version` key (default: V) from the index menu.

## 2. Syntax of Initialization Files

An initialization file consists of a series of commands. Each line of the file may contain one or more commands. When multiple commands are used, they must be separated by a semicolon (;).

Example 3.1. Multiple configuration commands per line

    set realname='Mutt user' ; ignore x-

The hash mark, or pound sign (“#”), is used as a “comment” character. You can use it to annotate your initialization file. All text after the comment character to the end of the line is ignored. For example,

Example 3.2. Commenting configuration files

    my_hdr X-Disclaimer: Why are you listening to me? # This is a comment

Single quotes (') and double quotes (") can be used to quote strings which contain spaces or other special characters. The difference between the two types of quotes is similar to that of many popular shell programs, namely that a single quote is used to specify a literal string (one that is not interpreted for shell variables or quoting with a backslash [see next paragraph]), while double quotes indicate a string for which should be evaluated. For example, backticks are evaluated inside of double quotes, but not for single quotes.

\ quotes the next character, just as in shells such as bash and zsh. For example, if want to put quotes “"” inside of a string, you can use “\” to force the next character to be a literal instead of interpreted character.

Example 3.3. Escaping quotes in congfiguration files

    set realname="Michael \"MuttDude\" Elkins"

“\\” means to insert a literal “\” into the line. “\n” and “\r” have their usual C meanings of linefeed and carriage-return, respectively.

A \ at the end of a line can be used to split commands over multiple lines, provided that the split points don't appear in the middle of command names.

It is also possible to substitute the output of a Unix command in an initialization file. This is accomplished by enclosing the command in backticks (``). For example,

Example 3.4. Using external command's output in configuration files

    my_hdr X-Operating-System: `uname -a`

The output of the Unix command “uname -a” will be substituted before the line is parsed.

### Note

Since initialization files are line oriented, only the first line of output from the Unix command will be substituted.

Both environment variables and mutt variables can be accessed by prepending “$” to the name of the variable. For example,

Example 3.5. Using environment variables in configuration files

    set record=+sent_on_$HOSTNAME

will cause mutt to save outgoing messages to a folder named “sent_on_kremvax” if the environment variable HOSTNAME is set to “kremvax.” (See $record for details.)

Mutt expands the variable when it is assigned, not when it is used. If the value of a variable on the right-hand side of an assignment changes after the assignment, the variable on the left-hand side will not be affected.

The commands understood by mutt are explained in the next paragraphs. For a complete list, see the command reference.

All configuration files are expected to be in the current locale as specified by the $charset variable which doesn't have a default value since it's determined by Mutt at startup. If a configuration file is not encoded in the same character set the $config_charset variable should be used: all lines starting with the next are recoded from $config_charset to $charset.

This mechanism should be avoided if possible as it has the following implications:

- These variables should be set early in a configuration file with $charset preceding $config_charset so Mutt know what character set to convert to.

- If $config_charset is set, it should be set in each configuration file because the value is global and not per configuration file.

- Because Mutt first recodes a line before it attempts to parse it, a conversion introducing question marks or other characters as part of errors (unconvertable characters, transliteration) may introduce syntax errors or silently change the meaning of certain tokens (e.g. inserting question marks into regular expressions).

## 3. Address groups

Usage:

`group` [ `-group` `name` ...] { `-rx` `expr` ... | `-addr` `expr` ... }

`ungroup` [ `-group` `name` ...] { `*` | `-rx` `expr` ... | `-addr` `expr` ... }

`group` is used to directly add either addresses or regular expressions to the specified group or groups. The different categories of arguments to the `group` command can be in any order. The flags `-rx` and `-addr` specify what the following strings (that cannot begin with a hyphen) should be interpreted as: either a regular expression or an email address, respectively.

These address groups can also be created implicitly by the alias, lists, subscribe and alternates commands by specifying the optional `-group` option.

Once defined, these address groups can be used in patterns to search for and limit the display to messages matching a group.

`ungroup` is used to remove addresses or regular expressions from the specified group or groups. The syntax is similar to the `group` command, however the special character `*` can be used to empty a group of all of its contents.

## 4. Defining/Using aliases

Usage:

`alias` [ `-group` `name` ...] `key` `address` [ `address` ...]

It's usually very cumbersome to remember or type out the address of someone you are communicating with. Mutt allows you to create “aliases” which map a short string to a full address.

### Note

If you want to create an alias for more than one address, you must separate the addresses with a comma (“,”).

The optional `-group` argument to `alias` causes the aliased address(es) to be added to the named group.

To remove an alias or aliases (“*” means all aliases):

`unalias` [ `-group` `name` ...] { `*` | `key` ... }

    alias muttdude me@cs.hmc.edu (Michael Elkins)
    alias theguys manny, moe, jack

Unlike other mailers, Mutt doesn't require aliases to be defined in a special file. The `alias` command can appear anywhere in a configuration file, as long as this file is sourced. Consequently, you can have multiple alias files, or you can have all aliases defined in your muttrc.

On the other hand, the `<create-alias>` function can use only one file, the one pointed to by the $alias_file variable (which is `˜/.muttrc` by default). This file is not special either, in the sense that Mutt will happily append aliases to any file, but in order for the new aliases to take effect you need to explicitly source this file too.

For example:

Example 3.6. Configuring external alias files

    source /usr/local/share/Mutt.aliases
    source ~/.mail_aliases
    set alias_file=~/.mail_aliases

To use aliases, you merely use the alias at any place in mutt where mutt prompts for addresses, such as the To: or Cc: prompt. You can also enter aliases in your editor at the appropriate headers if you have the $edit_headers variable set.

In addition, at the various address prompts, you can use the tab character to expand a partial alias to the full alias. If there are multiple matches, mutt will bring up a menu with the matching aliases. In order to be presented with the full list of aliases, you must hit tab with out a partial alias, such as at the beginning of the prompt or after a comma denoting multiple addresses.

In the alias menu, you can select as many aliases as you want with the `select-entry` key (default: <Return>), and use the exit key (default: q) to return to the address prompt.

## 5. Changing the default key bindings

Usage:

`bind` `map` `key` `function`

This command allows you to change the default key bindings (operation invoked when pressing a key).

map specifies in which menu the binding belongs. Multiple maps may be specified by separating them with commas (no additional whitespace is allowed). The currently defined maps are:

generic

  This is not a real menu, but is used as a fallback for all of the other menus except for the pager and editor modes. If a key is not defined in another menu, Mutt will look for a binding to use in this menu. This allows you to bind a key to a certain function in multiple menus instead of having multiple bind statements to accomplish the same task.

alias

  The alias menu is the list of your personal aliases as defined in your muttrc. It is the mapping from a short alias name to the full email address(es) of the recipient(s).

attach

  The attachment menu is used to access the attachments on received messages.

browser

  The browser is used for both browsing the local directory structure, and for listing all of your incoming mailboxes.

editor

  The editor is the line-based editor the user enters text data.

index

  The index is the list of messages contained in a mailbox.

compose

  The compose menu is the screen used when sending a new message.

pager

  The pager is the mode used to display message/attachment data, and help listings.

pgp

  The pgp menu is used to select the OpenPGP keys used to encrypt outgoing messages.

smime

  The smime menu is used to select the OpenSSL certificates used to encrypt outgoing messages.

postpone

  The postpone menu is similar to the index menu, except is used when recalling a message the user was composing, but saved until later.

query

  The query menu is the browser for results returned by $query_command.

mix

  The mixmaster screen is used to select remailer options for outgoing messages (if Mutt is compiled with Mixmaster support).

key is the key (or key sequence) you wish to bind. To specify a control character, use the sequence \Cx, where x is the letter of the control character (for example, to specify control-A use “\Ca”). Note that the case of x as well as \C is ignored, so that \CA, \Ca, \cA and \ca are all equivalent. An alternative form is to specify the key as a three digit octal number prefixed with a “\” (for example \177 is equivalent to \c?). In addition, key may be a symbolic name as shown in Table 3.1, “Symbolic key names”.

Table 3.1. Symbolic key names

Symbolic name | Meaning
--- | ---
\t | tab
<tab> | tab
<backtab> | backtab / shift-tab
\r | carriage return
\n | newline
\e | escape
<esc> | escape
<up> | up arrow
<down> | down arrow
<left> | left arrow
<right> | right arrow
<pageup> | Page Up
<pagedown> | Page Down
<backspace> | Backspace
<delete> | Delete
<insert> | Insert
<enter> | Enter
<return> | Return
<home> | Home
<end> | End
<space> | Space bar
<f1> | function key 1
<f10> | function key 10

key does not need to be enclosed in quotes unless it contains a space (“ ”) or semi-colon (“;”).

function specifies which action to take when key is pressed. For a complete list of functions, see the reference. The special function `<noop>` unbinds the specified key sequence.

## 6. Defining aliases for character sets

Usage:

`charset-hook` `alias` `charset`

`iconv-hook` `charset` `local-charset`

The `charset-hook` command defines an alias for a character set. This is useful to properly display messages which are tagged with a character set name not known to mutt.

The `iconv-hook` command defines a system-specific name for a character set. This is helpful when your systems character conversion library insists on using strange, system-specific names for character sets.

## 7. Setting variables based upon mailbox

Usage:

`folder-hook` `[!]regexp` `command`

It is often desirable to change settings based on which mailbox you are reading. The folder-hook command provides a method by which you can execute any configuration command. regexp is a regular expression specifying in which mailboxes to execute command before loading. If a mailbox matches multiple folder-hook's, they are executed in the order given in the muttrc.

### Note

If you use the “!” shortcut for $spoolfile at the beginning of the pattern, you must place it inside of double or single quotes in order to distinguish it from the logical not operator for the expression.

### Note

Settings are not restored when you leave the mailbox. For example, a command action to perform is to change the sorting method based upon the mailbox being read:

    folder-hook mutt set sort=threads

However, the sorting method is not restored to its previous value when reading a different mailbox. To specify a default command, use the pattern “.” before other folder-hooks adjusting a value on a per-folder basis because folder-hooks are evaluated in the order given in the configuration file. The following example will set the sort variable to `date-sent` for all folders but to `threads` for all folders containing “mutt” in their name.

Example 3.7. Setting sort method based on mailbox name

    folder-hook . set sort=date-sent
    folder-hook mutt set sort=threads

## 8. Keyboard macros

Usage:

`macro` `menu` `key` `sequence` [ `description` ]

Macros are useful when you would like a single key to perform a series of actions. When you press key in menu menu, Mutt will behave as if you had typed sequence. So if you have a common sequence of commands you type, you can create a macro to execute those commands with a single key or fewer keys.

menu is the map which the macro will be bound in. Multiple maps may be specified by separating multiple menu arguments by commas. Whitespace may not be used in between the menu arguments and the commas separating them.

key and sequence are expanded by the same rules as the key bindings with some additions. The first is that control characters in sequence can also be specified as ^x. In order to get a caret (“^”) you need to use ^^. Secondly, to specify a certain key such as up or to invoke a function directly, you can use the format <key name> and <function name>. For a listing of key names see the section on key bindings. Functions are listed in the reference.

The advantage with using function names directly is that the macros will work regardless of the current key bindings, so they are not dependent on the user having particular key definitions. This makes them more robust and portable, and also facilitates defining of macros in files used by more than one user (e.g., the system Muttrc).

Optionally you can specify a descriptive text after sequence, which is shown in the help screens.

### Note

Macro definitions (if any) listed in the help screen(s), are silently truncated at the screen width, and are not wrapped.

## 9. Using color and mono video attributes

Usage:

`color` `object` `foreground` `background`

`color` { `header` | `body` } `foreground` `background` `regexp`

`color` `index` `foreground` `background` `pattern`

`uncolor` `index` { `*` | `pattern` ... }

If your terminal supports color, you can spice up Mutt by creating your own color scheme. To define the color of an object (type of information), you must specify both a foreground color and a background color (it is not possible to only specify one or the other).

header and body match regexp in the header/body of a message, index matches pattern (see Section 2, “Patterns: Searching, Limiting and Tagging”) in the message index.

object can be one of:

- attachment

- bold (hiliting bold patterns in the body of messages)

- error (error messages printed by Mutt)

- hdrdefault (default color of the message header in the pager)

- indicator (arrow or bar used to indicate the current item in a menu)

- markers (the “+” markers at the beginning of wrapped lines in the pager)

- message (informational messages)

- normal

- quoted (text matching $quote_regexp in the body of a message)

- quoted1, quoted2, ..., quotedN (higher levels of quoting)

- search (hiliting of words in the pager)

- signature

- status (mode lines used to display info about the mailbox or message)

- tilde (the “˜” used to pad blank lines in the pager)

- tree (thread tree drawn in the message index and attachment menu)

- underline (hiliting underlined patterns in the body of messages)

foreground and background can be one of the following:

- white

- black

- green

- magenta

- blue

- cyan

- yellow

- red

- default

- colorx

foreground can optionally be prefixed with the keyword `bright` to make the foreground color boldfaced (e.g., `brightred`).

If your terminal supports it, the special keyword default can be used as a transparent color. The value brightdefault is also valid. If Mutt is linked against the S-Lang library, you also need to set the COLORFGBG environment variable to the default colors of your terminal for this to work; for example (for Bourne-like shells):

    set COLORFGBG="green;black"
    export COLORFGBG

### Note

The S-Lang library requires you to use the lightgray and brown keywords instead of white and yellow when setting this variable.

### Note

The uncolor command can be applied to the index object only. It removes entries from the list. You must specify the same pattern specified in the color command for it to be removed. The pattern “*” is a special token which means to clear the color index list of all entries.

Mutt also recognizes the keywords color0, color1, …, color N-1 (N being the number of colors supported by your terminal). This is useful when you remap the colors for your display (for example by changing the color associated with color2 for your xterm), since color names may then lose their normal meaning.

If your terminal does not support color, it is still possible change the video attributes through the use of the “mono” command:

Usage:

`mono` `object` `attribute`

`mono` { `header` | `body` } `attribute` `regexp`

`mono` `index` `attribute` `pattern`

`unmono` `index` { `*` | `pattern` ... }

For object, see the color command. attribute can be one of the following:

- none

- bold

- underline

- reverse

- standout

## 10. Message header display

Usage:

`ignore` `pattern` [ `pattern` ...]

`unignore` { `*` | `pattern` ... }

Messages often have many header fields added by automatic processing systems, or which may not seem useful to display on the screen. This command allows you to specify header fields which you don't normally want to see in the pager.

You do not need to specify the full header field name. For example, “ignore content-” will ignore all header fields that begin with the pattern “content-”. “ignore *” will ignore all headers.

To remove a previously added token from the list, use the “unignore” command. The “unignore” command will make Mutt display headers with the given pattern. For example, if you do “ignore x-” it is possible to “unignore x-mailer”.

“unignore *” will remove all tokens from the ignore list.

For example:

Example 3.8. Header weeding

    # Sven's draconian header weeding
    ignore *
    unignore from date subject to cc
    unignore organization organisation x-mailer: x-newsreader: x-mailing-list:
    unignore posted-to:

Usage:

`hdr_order` `header` [ `header` ...]

`unhdr_order` { `*` | `header` ... }

With the `hdr_order` command you can specify an order in which mutt will attempt to present these headers to you when viewing messages.

“unhdr_order *” will clear all previous headers from the order list, thus removing the header order effects set by the system-wide startup file.

Example 3.9. Configuring header display order

    hdr_order From Date: From: To: Cc: Subject:

## 11. Alternative addresses

Usage:

`alternates` [ `-group` `name` ...] `regexp` [ `regexp` ...]

`unalternates` [ `-group` `name` ...] { `*` | `regexp` ... }

With various functions, mutt will treat messages differently, depending on whether you sent them or whether you received them from someone else. For instance, when replying to a message that you sent to a different party, mutt will automatically suggest to send the response to the original message's recipients -- responding to yourself won't make much sense in many cases. (See $reply_to.)

Many users receive e-mail under a number of different addresses. To fully use mutt's features here, the program must be able to recognize what e-mail addresses you receive mail under. That's the purpose of the `alternates` command: It takes a list of regular expressions, each of which can identify an address under which you receive e-mail.

As addresses are matched using regular expressions and not exact strict comparisons, you should make sure you specify your addresses as precise as possible to avoid mismatches. For example, if you specify:

    alternates user@example

mutt will consider “`some-user@example`” as being your address, too which may not be desired. As a solution, in such cases addresses should be specified as:

    alternates '^user@example$'

The `-group` flag causes all of the subsequent regular expressions to be added to the named group.

The `unalternates` command can be used to write exceptions to `alternates` patterns. If an address matches something in an `alternates` command, but you nonetheless do not think it is from you, you can list a more precise pattern under an `unalternates` command.

To remove a regular expression from the `alternates` list, use the `unalternates` command with exactly the same regexp. Likewise, if the regexp for an `alternates` command matches an entry on the `unalternates` list, that `unalternates` entry will be removed. If the regexp for `unalternates` is “*”, all entries on `alternates` will be removed.

## 12. Mailing lists

Usage:

`lists` [ `-group` `name` ...] `regexp` [ `regexp` ...]

`unlists` [ `-group` `name` ...] { `*` | `regexp` ... }

`subscribe` [ `-group` `name` ...] `regexp` [ `regexp` ...]

`unsubscribe` [ `-group` `name` ...] { `*` | `regexp` ... }

Mutt has a few nice features for handling mailing lists. In order to take advantage of them, you must specify which addresses belong to mailing lists, and which mailing lists you are subscribed to. Once you have done this, the `<list-reply>` function will work for all known lists. Additionally, when you send a message to a subscribed list, mutt will add a Mail-Followup-To header to tell other users' mail user agents not to send copies of replies to your personal address.

### Note

The Mail-Followup-To header is a non-standard extension which is not supported by all mail user agents. Adding it is not bullet-proof against receiving personal CCs of list messages. Also note that the generation of the Mail-Followup-To header is controlled by the $followup_to configuration variable.

More precisely, Mutt maintains lists of patterns for the addresses of known and subscribed mailing lists. Every subscribed mailing list is known. To mark a mailing list as known, use the “lists” command. To mark it as subscribed, use “subscribe”.

You can use regular expressions with both commands. To mark all messages sent to a specific bug report's address on mutt's bug tracking system as list mail, for instance, you could say “subscribe [0-9]*@bugs.guug.de”. Often, it's sufficient to just give a portion of the list's e-mail address.

Specify as much of the address as you need to to remove ambiguity. For example, if you've subscribed to the Mutt mailing list, you will receive mail addressed to mutt-users@mutt.org. So, to tell Mutt that this is a mailing list, you could add “lists mutt-users@” to your initialization file. To tell mutt that you are subscribed to it, add “subscribe mutt-users” to your initialization file instead. If you also happen to get mail from someone whose address is mutt-users@example.com, you could use “lists ^mutt-users@mutt\\.org$” or “subscribe ^mutt-users@mutt\\.org$” to match only mail from the actual list.

The `-group` flag adds all of the subsequent regular expressions to the named group.

The “unlists” command is used to remove a token from the list of known and subscribed mailing-lists. Use “unlists *” to remove all tokens.

To remove a mailing list from the list of subscribed mailing lists, but keep it on the list of known mailing lists, use “unsubscribe”.

## 13. Using Multiple spool mailboxes

Usage:

`mbox-hook` `[!]pattern` `mailbox`

This command is used to move read messages from a specified mailbox to a different mailbox automatically when you quit or change folders. pattern is a regular expression specifying the mailbox to treat as a “spool” mailbox and mailbox specifies where mail should be saved when read.

Unlike some of the other hook commands, only the first matching pattern is used (it is not possible to save read mail in more than a single mailbox).

## 14. Monitoring incoming mail

Usage:

`mailboxes` `mailbox` [ `mailbox` ...]

`unmailboxes` { `*` | `mailbox` ... }

This command specifies folders which can receive mail and which will be checked for new messages periodically.

folder can either be a local file or directory (Mbox/Mmdf or Maildir/Mh). If Mutt was built with POP and/or IMAP support, folder can also be a POP/IMAP folder URL. The URL syntax is described in Section 1.2, “URL syntax”, POP and IMAP are described in Section 3, “POP3 Support” and Section 4, “IMAP Support” respectively.

Mutt provides a number of advanced features for handling (possibly many) folders and new mail within them, please refer to Section 9, “Handling multiple folders” for details (including in what situations and how often Mutt checks for new mail).

The “unmailboxes” command is used to remove a token from the list of folders which receive mail. Use “unmailboxes *” to remove all tokens.

### Note

The folders in the `mailboxes` command are resolved when the command is executed, so if these names contain shortcut characters (such as “=” and “!”), any variable definition that affects these characters (like $folder and $spoolfile) should be set before the `mailboxes` command. If none of these shorcuts are used, a local path should be absolute as otherwise mutt tries to find it relative to the directory from where mutt was started which may not always be desired.

For Mbox and Mmdf folders, new mail is detected by comparing access and/or modification times of files: Mutt assumes a folder has new mail if it wasn't accessed after it was last modified. Utilities like `biff` or `frm` or any other program which accesses the mailbox might cause Mutt to never detect new mail for that mailbox if they do not properly reset the access time. Other possible causes of Mutt not detecting new mail in these folders are backup tools (updating access times) or filesystems mounted without access time update support.

In cases where new mail detection for Mbox or Mmdf folders appears to be unreliable, the $check_mbox_size option can be used to make Mutt track and consult file sizes for new mail detection instead.

## 15. User defined headers

Usage:

`my_hdr` `string`

`unmy_hdr` { `*` | `field` ... }

The `my_hdr` command allows you to create your own header fields which will be added to every message you send.

For example, if you would like to add an “Organization:” header field to all of your outgoing messages, you can put the command

Example 3.10. Defining custom headers

    my_hdr Organization: A Really Big Company, Anytown, USA

in your `.muttrc`.

### Note

Space characters are not allowed between the keyword and the colon (“:”). The standard for electronic mail (RFC2822) says that space is illegal there, so Mutt enforces the rule.

If you would like to add a header field to a single message, you should either set the $edit_headers variable, or use the `<edit-headers>` function (default: “E”) in the compose menu so that you can edit the header of your message along with the body.

To remove user defined header fields, use the `unmy_hdr` command. You may specify an asterisk (“*”) to remove all header fields, or the fields to remove. For example, to remove all “To” and “Cc” header fields, you could use:

    unmy_hdr to cc

## 16. Specify default save mailbox

Usage:

`save-hook` `[!]pattern` `mailbox`

This command is used to override the default mailbox used when saving messages. mailbox will be used as the default if the message matches pattern, see Message Matching in Hooks for information on the exact format.

To provide more flexibility and good defaults, Mutt applies the expandos of $index_format to mailbox after it was expanded.

Examples:

Example 3.11. Using %-expandos in `save-hook`

    # default: save all to ~/Mail/<author name>
    save-hook . ~/Mail/%F

    # save from me@turing.cs.hmc.edu and me@cs.hmc.edu to $folder/elkins
    save-hook me@(turing\\.)?cs\\.hmc\\.edu$ +elkins

    # save from aol.com to $folder/spam
    save-hook aol\\.com$ +spam

Also see the fcc-save-hook command.

## 17. Specify default Fcc: mailbox when composing

Usage:

`fcc-hook` `[!]pattern` `mailbox`

This command is used to save outgoing mail in a mailbox other than $record. Mutt searches the initial list of message recipients for the first matching regexp and uses mailbox as the default Fcc: mailbox. If no match is found the message will be saved to $record mailbox.

To provide more flexibility and good defaults, Mutt applies the expandos of $index_format to mailbox after it was expanded.

See Message Matching in Hooks for information on the exact format of pattern.

Example: `fcc-hook [@.]aol\\.com$ +spammers`

The above will save a copy of all messages going to the aol.com domain to the `+spammers' mailbox by default. Also see the fcc-save-hook command.

## 18. Specify default save filename and default Fcc: mailbox at once

Usage:

`fcc-save-hook` `[!]pattern` `mailbox`

This command is a shortcut, equivalent to doing both a fcc-hook and a save-hook with its arguments, including %-expansion on mailbox according to $index_format.

## 19. Change settings based upon message recipients

Usage:

`reply-hook` `[!]pattern` `command`

`send-hook` `[!]pattern` `command`

`send2-hook` `[!]pattern` `command`

These commands can be used to execute arbitrary configuration commands based upon recipients of the message. pattern is used to match the message, see Message Matching in Hooks for details. command is executed when pattern matches.

`reply-hook` is matched against the message you are replying to, instead of the message you are sending. `send-hook` is matched against all messages, both new and replies.

### Note

`reply-hook`s are matched before the `send-hook`, regardless of the order specified in the user's configuration file.

`send2-hook` is matched every time a message is changed, either by editing it, or by using the compose menu to change its recipients or subject. `send2-hook` is executed after `send-hook`, and can, e.g., be used to set parameters such as the $sendmail variable depending on the message's sender address.

For each type of `send-hook` or `reply-hook`, when multiple matches occur, commands are executed in the order they are specified in the muttrc (for that type of hook).

Example: `send-hook mutt "set mime_forward signature=''"`

Another typical use for this command is to change the values of the $attribution, $signature and $locale variables in order to change the language of the attributions and signatures based upon the recipients.

### Note

send-hook's are only executed once after getting the initial list of recipients. Adding a recipient after replying or editing the message will not cause any send-hook to be executed. Also note that `my_hdr` commands which modify recipient headers, or the message's subject, don't have any effect on the current message when executed from a send-hook.

## 20. Change settings before formatting a message

Usage:

`message-hook` `[!]pattern` `command`

This command can be used to execute arbitrary configuration commands before viewing or formatting a message based upon information about the message. command is executed if the pattern matches the message to be displayed. When multiple matches occur, commands are executed in the order they are specified in the muttrc.

See Message Matching in Hooks for information on the exact format of pattern.

Example:

    message-hook ~A 'set pager=builtin'
    message-hook '~f freshmeat-news' 'set pager="less \"+/^  subject: .*\""'

## 21. Choosing the cryptographic key of the recipient

Usage:

`crypt-hook` `pattern` `keyid`

When encrypting messages with PGP/GnuPG or OpenSSL, you may want to associate a certain key with a given e-mail address automatically, either because the recipient's public key can't be deduced from the destination address, or because, for some reasons, you need to override the key Mutt would normally use. The `crypt-hook` command provides a method by which you can specify the ID of the public key to be used when encrypting messages to a certain recipient.

The meaning of keyid is to be taken broadly in this context: You can either put a numerical key ID here, an e-mail address, or even just a real name.

## 22. Adding key sequences to the keyboard buffer

Usage:

`push` `string`

This command adds the named string to the keyboard buffer. The string may contain control characters, key names and function names like the sequence string in the macro command. You may use it to automatically run a sequence of commands at startup, or when entering certain folders. For example, the following command will automatically collapse all threads when entering a folder:

Example 3.12. Embedding `push` in `folder-hook`

    folder-hook . 'push <collapse-all>'

## 23. Executing functions

Usage:

`exec` `function` [ `function` ...]

This command can be used to execute any function. Functions are listed in the function reference. “exec function” is equivalent to “push <function>”.

## 24. Message Scoring

Usage:

`score` `pattern` `value`

`unscore` { `*` | `pattern` ... }

The `score` commands adds value to a message's score if pattern matches it. pattern is a string in the format described in the patterns section (note: For efficiency reasons, patterns which scan information not available in the index, such as `˜b`, `˜B` or `˜h`, may not be used). value is a positive or negative integer. A message's final score is the sum total of all matching `score` entries. However, you may optionally prefix value with an equal sign (=) to cause evaluation to stop at a particular entry if there is a match. Negative final scores are rounded up to 0.

The `unscore` command removes score entries from the list. You must specify the same pattern specified in the `score` command for it to be removed. The pattern “*” is a special token which means to clear the list of all score entries.

## 25. Spam detection

Usage:

`spam` `pattern` `format`

`nospam` { `*` | `pattern` }

Mutt has generalized support for external spam-scoring filters. By defining your spam patterns with the `spam` and `nospam` commands, you can limit, search, and sort your mail based on its spam attributes, as determined by the external filter. You also can display the spam attributes in your index display using the `%H` selector in the $index_format variable. (Tip: try `%?H?[%H] ?` to display spam tags only when they are defined for a given message.)

Your first step is to define your external filter's spam patterns using the `spam` command. pattern should be a regular expression that matches a header in a mail message. If any message in the mailbox matches this regular expression, it will receive a “spam tag” or “spam attribute” (unless it also matches a `nospam` pattern -- see below.) The appearance of this attribute is entirely up to you, and is governed by the format parameter. format can be any static text, but it also can include back-references from the pattern expression. (A regular expression “back-reference” refers to a sub-expression contained within parentheses.) `%1` is replaced with the first back-reference in the regex, `%2` with the second, etc.

If you're using multiple spam filters, a message can have more than one spam-related header. You can define `spam` patterns for each filter you use. If a message matches two or more of these patterns, and the $spam_separator variable is set to a string, then the message's spam tag will consist of all the format strings joined together, with the value of $spam_separator separating them.

For example, suppose I use DCC, SpamAssassin, and PureMessage. I might define these spam settings:

Example 3.13. Configuring spam detection

    spam "X-DCC-.*-Metrics:.*(....)=many"         "90+/DCC-%1"
    spam "X-Spam-Status: Yes"                     "90+/SA"
    spam "X-PerlMX-Spam: .*Probability=([0-9]+)%" "%1/PM"
    set spam_separator=", "

If I then received a message that DCC registered with “many” hits under the “Fuz2” checksum, and that PureMessage registered with a 97% probability of being spam, that message's spam tag would read `90+/DCC-Fuz2, 97/PM`. (The four characters before “=many” in a DCC report indicate the checksum used -- in this case, “Fuz2”.)

If the $spam_separator variable is unset, then each spam pattern match supersedes the previous one. Instead of getting joined format strings, you'll get only the last one to match.

The spam tag is what will be displayed in the index when you use `%H` in the `$index_format` variable. It's also the string that the `˜H` pattern-matching expression matches against for `<search>` and `<limit>` functions. And it's what sorting by spam attribute will use as a sort key.

That's a pretty complicated example, and most people's actual environments will have only one spam filter. The simpler your configuration, the more effective mutt can be, especially when it comes to sorting.

Generally, when you sort by spam tag, mutt will sort lexically -- that is, by ordering strings alphanumerically. However, if a spam tag begins with a number, mutt will sort numerically first, and lexically only when two numbers are equal in value. (This is like UNIX's `sort -n`.) A message with no spam attributes at all -- that is, one that didn't match any of your `spam` patterns -- is sorted at lowest priority. Numbers are sorted next, beginning with 0 and ranging upward. Finally, non-numeric strings are sorted, with “a” taking lower priority than “z”. Clearly, in general, sorting by spam tags is most effective when you can coerce your filter to give you a raw number. But in case you can't, mutt can still do something useful.

The `nospam` command can be used to write exceptions to `spam` patterns. If a header pattern matches something in a `spam` command, but you nonetheless do not want it to receive a spam tag, you can list a more precise pattern under a `nospam` command.

If the pattern given to `nospam` is exactly the same as the pattern on an existing `spam` list entry, the effect will be to remove the entry from the spam list, instead of adding an exception. Likewise, if the pattern for a `spam` command matches an entry on the `nospam` list, that `nospam` entry will be removed. If the pattern for `nospam` is “*”, all entries on both lists will be removed. This might be the default action if you use `spam` and `nospam` in conjunction with a `folder-hook`.

You can have as many `spam` or `nospam` commands as you like. You can even do your own primitive spam detection within mutt -- for example, if you consider all mail from `MAILER-DAEMON` to be spam, you can use a `spam` command like this:

    spam "^From: .*MAILER-DAEMON"       "999"

## 26. Setting and Querying Variables

### 26.1. Commands

The following commands are available to manipulate and query variables:

Usage:

`set` { [ `no` | `inv` ] `variable` | `variable=value` } [...]

`toggle` `variable` [ `variable` ...]

`unset` `variable` [ `variable` ...]

`reset` `variable` [ `variable` ...]

This command is used to set (and unset) configuration variables. There are four basic types of variables: boolean, number, string and quadoption. boolean variables can be set (true) or unset (false). number variables can be assigned a positive integer value. string variables consist of any number of printable characters and must be enclosed in quotes if they contain spaces or tabs. You may also use the escape sequences “\n” and “\t” for newline and tab, respectively. quadoption variables are used to control whether or not to be prompted for certain actions, or to specify a default action. A value of yes will cause the action to be carried out automatically as if you had answered yes to the question. Similarly, a value of no will cause the action to be carried out as if you had answered “no.” A value of ask-yes will cause a prompt with a default answer of “yes” and ask-no will provide a default answer of “no.”

Prefixing a variable with “no” will unset it. Example: `set noaskbcc`.

For boolean variables, you may optionally prefix the variable name with `inv` to toggle the value (on or off). This is useful when writing macros. Example: `set invsmart_wrap`.

The `toggle` command automatically prepends the `inv` prefix to all specified variables.

The `unset` command automatically prepends the `no` prefix to all specified variables.

Using the `<enter-command>` function in the index menu, you can query the value of a variable by prefixing the name of the variable with a question mark:

    set ?allow_8bit

The question mark is actually only required for boolean and quadoption variables.

The `reset` command resets all given variables to the compile time defaults (hopefully mentioned in this manual). If you use the command `set` and prefix the variable with “&” this has the same behavior as the reset command.

With the `reset` command there exists the special variable “all”, which allows you to reset all variables to their system defaults.

### 26.2. User-defined variables

#### 26.2.1. Introduction

Along with the variables listed in the Configuration variables section, mutt supports user-defined variables with names starting with `my_` as in, for example, `my_cfgdir`.

The `set` command either creates a custom `my_` variable or changes its value if it does exist already. The `unset` and `reset` commands remove the variable entirely.

Since user-defined variables are expanded in the same way that environment variables are (except for the shell-escape command and backtick expansion), this feature can be used to make configuration files more readable.

#### 26.2.2. Examples

The following example defines and uses the variable `my_cfgdir` to abbreviate the calls of the source command:

Example 3.14. Using user-defined variables for config file readability

    set my_cfgdir = $HOME/mutt/config

    source $my_cfgdir/hooks
    source $my_cfgdir/macros
    # more source commands...

A custom variable can also be used in macros to backup the current value of another variable. In the following example, the value of the $delete is changed temporarily while its original value is saved as `my_delete`. After the macro has executed all commands, the original value of $delete is restored.

Example 3.15. Using user-defined variables for backing up other config option values

    macro pager ,x '\
    <enter-command>set my_delete=$delete<enter>\
    <enter-command>set delete=yes<enter>\
    ...\
    <enter-command>set delete=$my_delete<enter>'

Since mutt expands such values already when parsing the configuration file(s), the value of `$my_delete` in the last example would be the value of `$delete` exactly as it was at that point during parsing the configuration file. If another statement would change the value for `$delete` later in the same or another file, it would have no effect on `$my_delete`. However, the expansion can be deferred to runtime, as shown in the next example, when escaping the dollar sign.

Example 3.16. Deferring user-defined variable expansion to runtime

    macro pager <PageDown> "\
    <enter-command> set my_old_pager_stop=\$pager_stop pager_stop<Enter>\
    <next-page>\
    <enter-command> set pager_stop=\$my_old_pager_stop<Enter>\
    <enter-command> unset my_old_pager_stop<Enter>"

Note that there is a space between `<enter-command>` and the `set` configuration command, preventing mutt from recording the macro's commands into its history.

## 27. Reading initialization commands from another file

Usage:

`source` `filename`

This command allows the inclusion of initialization commands from other files. For example, I place all of my aliases in `˜/.mail_aliases` so that I can make my `˜/.muttrc` readable and keep my aliases private.

If the filename begins with a tilde (“˜”), it will be expanded to the path of your home directory.

If the filename ends with a vertical bar (|), then filename is considered to be an executable program from which to read input (eg. `source ˜/bin/myscript|`).

## 28. Removing hooks

Usage:

`unhook` { `*` | `hook-type` }

This command permits you to flush hooks you have previously defined. You can either remove all hooks by giving the “*” character as an argument, or you can remove all hooks of a specific type by saying something like `unhook send-hook`.

## 29. Format Strings

### 29.1. Basic usage

Format strings are a general concept you'll find in several locations through the mutt configuration, especially in the $index_format, $pager_format, $status_format, and other “*_format” variables. These can be very straightforward, and it's quite possible you already know how to use them.

The most basic format string element is a percent symbol followed by another character. For example, `%s` represents a message's Subject: header in the $index_format variable. The “expandos” available are documented with each format variable, but there are general modifiers available with all formatting expandos, too. Those are our concern here.

Some of the modifiers are borrowed right out of C (though you might know them from Perl, Python, shell, or another language). These are the [-]m.n modifiers, as in `%-12.12s`. As with such programming languages, these modifiers allow you to specify the minimum and maximum size of the resulting string, as well as its justification. If the “-” sign follows the percent, the string will be left-justified instead of right-justified. If there's a number immediately following that, it's the minimum amount of space the formatted string will occupy -- if it's naturally smaller than that, it will be padded out with spaces. If a decimal point and another number follow, that's the maximum space allowable -- the string will not be permitted to exceed that width, no matter its natural size. Each of these three elements is optional, so that all these are legal format strings: `%-12s` `%4c` `%.15F` `%-12.15L`

Mutt adds some other modifiers to format strings. If you use an equals symbol (`=`) as a numeric prefix (like the minus above), it will force the string to be centered within its minimum space range. For example, `%=14y` will reserve 14 characters for the %y expansion -- that's the X-Label: header, in `$index_format`. If the expansion results in a string less than 14 characters, it will be centered in a 14-character space. If the X-Label for a message were "test", that expansion would look like “ test ”.

There are two very little-known modifiers that affect the way that an expando is replaced. If there is an underline (“_”) character between any format modifiers (as above) and the expando letter, it will expands in all lower case. And if you use a colon (“:”), it will replace all decimal points with underlines.

### 29.2. Filters

Any format string ending in a vertical bar (“|”) will be expanded and piped through the first word in the string, using spaces as separator. The string returned will be used for display. If the returned string ends in %, it will be passed through the formatter a second time. This allows the filter to generate a replacement format string including % expandos.

All % expandos in a format string are expanded before the script is called so that:

Example 3.17. Using external filters in format strings

    set status_format="script.sh '%r %f (%L)'|"

will make mutt expand `%r`, `%f` and `%L` before calling the script. The example also shows that arguments can be quoted: the script will receive the expanded string between the single quotes as the only argument.

A practical example is the `mutt_xtitle` script installed in the `samples` subdirectory of the mutt documentation: it can be used as filter for `$status_format` to set the current terminal's title, if supported.

## Chapter 4. Advanced Usage

## 1. Regular Expressions

All string patterns in Mutt including those in more complex patterns must be specified using regular expressions (regexp) in the “POSIX extended” syntax (which is more or less the syntax used by egrep and GNU awk). For your convenience, we have included below a brief description of this syntax.

The search is case sensitive if the pattern contains at least one upper case letter, and case insensitive otherwise.

### Note

Note that “\” must be quoted if used for a regular expression in an initialization command: “\\”.

A regular expression is a pattern that describes a set of strings. Regular expressions are constructed analogously to arithmetic expressions, by using various operators to combine smaller expressions.

### Note

Note that the regular expression can be enclosed/delimited by either " or ' which is useful if the regular expression includes a white-space character. See Syntax of Initialization Files for more information on " and ' delimiter processing. To match a literal " or ' you must preface it with \ (backslash).

The fundamental building blocks are the regular expressions that match a single character. Most characters, including all letters and digits, are regular expressions that match themselves. Any metacharacter with special meaning may be quoted by preceding it with a backslash.

The period “.” matches any single character. The caret “^” and the dollar sign “$” are metacharacters that respectively match the empty string at the beginning and end of a line.

A list of characters enclosed by “[” and “]” matches any single character in that list; if the first character of the list is a caret “^” then it matches any character not in the list. For example, the regular expression [0123456789] matches any single digit. A range of ASCII characters may be specified by giving the first and last characters, separated by a hyphen “-”. Most metacharacters lose their special meaning inside lists. To include a literal “]” place it first in the list. Similarly, to include a literal “^” place it anywhere but first. Finally, to include a literal hyphen “-” place it last.

Certain named classes of characters are predefined. Character classes consist of “[:”, a keyword denoting the class, and “:]”. The following classes are defined by the POSIX standard in Table 4.1, “POSIX regular expression character classes”

Table 4.1. POSIX regular expression character classes

Character class | Description
--- | ---
[:alnum:] | Alphanumeric characters
[:alpha:] | Alphabetic characters
[:blank:] | Space or tab characters
[:cntrl:] | Control characters
[:digit:] | Numeric characters
[:graph:] | Characters that are both printable and visible. (A space is printable, but not visible, while an “a” is both)
[:lower:] | Lower-case alphabetic characters
[:print:] | Printable characters (characters that are not control characters)
[:punct:] | Punctuation characters (characters that are not letter, digits, control characters, or space characters)
[:space:] | Space characters (such as space, tab and formfeed, to name a few)
[:upper:] | Upper-case alphabetic characters
[:xdigit:] | Characters that are hexadecimal digits

A character class is only valid in a regular expression inside the brackets of a character list.

### Note

Note that the brackets in these class names are part of the symbolic names, and must be included in addition to the brackets delimiting the bracket list. For example, [[:digit:]] is equivalent to [0-9].

Two additional special sequences can appear in character lists. These apply to non-ASCII character sets, which can have single symbols (called collating elements) that are represented with more than one character, as well as several characters that are equivalent for collating or sorting purposes:

Collating Symbols

  A collating symbol is a multi-character collating element enclosed in “[.” and “.]”. For example, if “ch” is a collating element, then [[.ch.]] is a regexp that matches this collating element, while [ch] is a regexp that matches either “c” or “h”.

Equivalence Classes

  An equivalence class is a locale-specific name for a list of characters that are equivalent. The name is enclosed in “[=” and “=]”. For example, the name “e” might be used to represent all of “è” “é” and “e”. In this case, [[=e=]] is a regexp that matches any of “è”, “é” and “e”.

A regular expression matching a single character may be followed by one of several repetition operators described in Table 4.2, “Regular expression repetition operators”.

Table 4.2. Regular expression repetition operators

Operator | Description
--- | ---
? | The preceding item is optional and matched at most once
* | The preceding item will be matched zero or more times
+ | The preceding item will be matched one or more times
{n} | The preceding item is matched exactly n times
{n,} | The preceding item is matched n or more times
{,m} | The preceding item is matched at most m times
{n,m} | The preceding item is matched at least n times, but no more than m times

Two regular expressions may be concatenated; the resulting regular expression matches any string formed by concatenating two substrings that respectively match the concatenated subexpressions.

Two regular expressions may be joined by the infix operator “|”; the resulting regular expression matches any string matching either subexpression.

Repetition takes precedence over concatenation, which in turn takes precedence over alternation. A whole subexpression may be enclosed in parentheses to override these precedence rules.

### Note

If you compile Mutt with the GNU rx package, the following operators may also be used in regular expressions as described in Table 4.3, “GNU regular expression extensions”.

Table 4.3. GNU regular expression extensions

Expression | Description
--- | ---
\\y | Matches the empty string at either the beginning or the end of a word
\\B | Matches the empty string within a word
\\< | Matches the empty string at the beginning of a word
\\> | Matches the empty string at the end of a word
\\w | Matches any word-constituent character (letter, digit, or underscore)
\\W | Matches any character that is not word-constituent
\\` | Matches the empty string at the beginning of a buffer (string)
\\' | Matches the empty string at the end of a buffer

Please note however that these operators are not defined by POSIX, so they may or may not be available in stock libraries on various systems.

## 2. Patterns: Searching, Limiting and Tagging

Many of Mutt's commands allow you to specify a pattern to match (`limit`, `tag-pattern`, `delete-pattern`, etc.). Table 4.4, “Pattern modifiers” shows several ways to select messages.

Table 4.4. Pattern modifiers

Pattern modifier | Description
--- | ---
~A | all messages
~b EXPR | messages which contain EXPR in the message body
=b STRING | messages which contain STRING in the message body. If IMAP is enabled, searches for STRING on the server, rather than downloading each message and searching it locally.
~B EXPR | messages which contain EXPR in the whole message
~c EXPR | messages carbon-copied to EXPR
%c GROUP | messages carbon-copied to any member of GROUP
~C EXPR | messages either to: or cc: EXPR
%C GROUP | messages either to: or cc: to any member of GROUP
~d [MIN]-[MAX] | messages with “date-sent” in a Date range
~D | deleted messages
~e EXPR | messages which contains EXPR in the “Sender” field
%e GROUP | messages which contain a member of GROUP in the “Sender” field
~E | expired messages
~F | flagged messages
~f EXPR | messages originating from EXPR
%f GROUP | messages originating from any member of GROUP
~g | cryptographically signed messages
~G | cryptographically encrypted messages
~h EXPR | messages which contain EXPR in the message header
~H EXPR | messages with a spam attribute matching EXPR
~i EXPR | messages which match EXPR in the “Message-ID” field
~k | messages which contain PGP key material
~L EXPR | messages either originated or received by EXPR
%L GROUP | message either originated or received by any member of GROUP
~l | messages addressed to a known mailing list
~m [MIN]-[MAX] | messages in the range MIN to MAX *)
~n [MIN]-[MAX] | messages with a score in the range MIN to MAX *)
~N | new messages
~O | old messages
~p | messages addressed to you (consults alternates)
~P | messages from you (consults alternates)
~Q | messages which have been replied to
~r [MIN]-[MAX] | messages with “date-received” in a Date range
~R | read messages
~s EXPR | messages having EXPR in the “Subject” field.
~S | superseded messages
~t EXPR | messages addressed to EXPR
~T | tagged messages
~u | messages addressed to a subscribed mailing list
~U | unread messages
~v | messages part of a collapsed thread.
~V | cryptographically verified messages
~x EXPR | messages which contain EXPR in the “References” field
~X [MIN]-[MAX] | messages with MIN to MAX attachments *)
~y EXPR | messages which contain EXPR in the “X-Label” field
~z [MIN]-[MAX] | messages with a size in the range MIN to MAX *)
~= | duplicated messages (see $duplicate_threads)
~$ | unreferenced messages (requires threaded view)
~(PATTERN) | messages in threads containing messages matching PATTERN, e.g. all threads containing messages from you: ~(~P)

Where EXPR is a regular expression. Special attention has to be made when using regular expressions inside of patterns. Specifically, Mutt's parser for these patterns will strip one level of backslash (“\”), which is normally used for quoting. If it is your intention to use a backslash in the regular expression, you will need to use two backslashes instead (“\\”). You can force mutt to treat EXPR as a simple string instead of a regular expression by using = instead of ˜ in the pattern name. For example, `=b *.*` will find all messages that contain the literal string “*.*”. Simple string matches are less powerful than regular expressions but can be considerably faster. This is especially true for IMAP folders, because string matches can be performed on the server instead of by fetching every message. IMAP treats `=h` specially: it must be of the form "header: substring" and will not partially match header names. The substring part may be omitted if you simply wish to find messages containing a particular header without regard to its value.

*) The forms “<[MAX]”, “>[MIN]”, “[MIN]-” and “-[MAX]” are allowed, too.

### 2.1. Pattern Modifier

### Note

Note that patterns matching 'lists' of addresses (notably c, C, p, P and t) match if there is at least one match in the whole list. If you want to make sure that all elements of that list match, you need to prefix your pattern with “^”. This example matches all mails which only has recipients from Germany.

    ^~C \.de$

### 2.2. Simple Patterns

Mutt supports two versions of so called “simple searches” which are issued if the query entered for searching, limiting and similar operations does not seem to be a valid pattern (i.e. it does not contain one of these characters: “˜”, “=” or “%”). If the query is supposed to contain one of these special characters, they must be escaped by prepending a backslash (“\”).

The first type is by checking whether the query string equals a keyword case-insensitively from Table 4.5, “Simple search keywords”: If that is the case, Mutt will use the shown pattern modifier instead. If a keyword would conflict with your search keyword, you need to turn it into a regular expression to avoid matching the keyword table. For example, if you want to find all messages matching “flag” (using $simple_search) but don't want to match flagged messages, simply search for “`[f]lag`”.

Table 4.5. Simple search keywords

Keyword | Pattern modifier
--- | ---
all | ~A
. | ~A
^ | ~A
del | ~D
flag | ~F
new | ~N
old | ~O
repl | ~Q
read | ~R
tag | ~T
unread | ~U

The second type of simple search is to build a complex search pattern using $simple_search as a template. Mutt will insert your query properly quoted and search for the composed complex query.

### 2.3. Complex Patterns

Logical AND is performed by specifying more than one criterion. For example:

    ~t mutt ~f elkins

would select messages which contain the word “mutt” in the list of recipients and that have the word “elkins” in the “From” header field.

Mutt also recognizes the following operators to create more complex search patterns:

- ! -- logical NOT operator

- | -- logical OR operator

- () -- logical grouping operator

Here is an example illustrating a complex search pattern. This pattern will select all messages which do not contain “mutt” in the “To” or “Cc” field and which are from “elkins”.

Example 4.1. Using boolean operators in patterns

    !(~t mutt|~c mutt) ~f elkins

Here is an example using white space in the regular expression (note the ' and " delimiters). For this to match, the mail's subject must match the “^Junk +From +Me$” and it must be from either “Jim +Somebody” or “Ed +SomeoneElse”:

     '~s "^Junk +From +Me$" ~f ("Jim +Somebody"|"Ed +SomeoneElse")'

### Note

If a regular expression contains parenthesis, or a vertical bar ("|"), you must enclose the expression in double or single quotes since those characters are also used to separate different parts of Mutt's pattern language. For example: `~f "me@(mutt\.org|cs\.hmc\.edu)"`

Without the quotes, the parenthesis wouldn't end. This would be separated to two OR'd patterns: ˜f me@(mutt\.org and cs\.hmc\.edu). They are never what you want.

### 2.4. Searching by Date

Mutt supports two types of dates, absolute and relative.

Absolute. Dates must be in DD/MM/YY format (month and year are optional, defaulting to the current month and year). An example of a valid range of dates is:

    Limit to messages matching: ~d 20/1/95-31/10

If you omit the minimum (first) date, and just specify “-DD/MM/YY”, all messages before the given date will be selected. If you omit the maximum (second) date, and specify “DD/MM/YY-”, all messages after the given date will be selected. If you specify a single date with no dash (“-”), only messages sent on the given date will be selected.

Error Margins. You can add error margins to absolute dates. An error margin is a sign (+ or -), followed by a digit, followed by one of the units in Table 4.6, “Date units”. As a special case, you can replace the sign by a “*” character, which is equivalent to giving identical plus and minus error margins.

Table 4.6. Date units

Unit | Description
--- | ---
y | Years
m | Months
w | Weeks
d | Days

Example: To select any messages two weeks around January 15, 2001, you'd use the following pattern:

    Limit to messages matching: ~d 15/1/2001*2w

Relative. This type of date is relative to the current date, and may be specified as:

- >offset (messages older than offset units)

- <offset (messages newer than offset units)

- =offset (messages exactly offset units old)

offset is specified as a positive number with one of the units from Table 4.6, “Date units”.

Example: to select messages less than 1 month old, you would use

    Limit to messages matching: ~d <1m

### Note

All dates used when searching are relative to the local time zone, so unless you change the setting of your $index_format to include a `%[...]` format, these are not the dates shown in the main index.

## 3. Using Tags

Sometimes it is desirable to perform an operation on a group of messages all at once rather than one at a time. An example might be to save messages to a mailing list to a separate folder, or to delete all messages with a given subject. To tag all messages matching a pattern, use the `<tag-pattern>` function, which is bound to “shift-T” by default. Or you can select individual messages by hand using the `<tag-message>` function, which is bound to “t” by default. See patterns for Mutt's pattern matching syntax.

Once you have tagged the desired messages, you can use the “tag-prefix” operator, which is the “;” (semicolon) key by default. When the “tag-prefix” operator is used, the next operation will be applied to all tagged messages if that operation can be used in that manner. If the $auto_tag variable is set, the next operation applies to the tagged messages automatically, without requiring the “tag-prefix”.

In macros or push commands, you can use the “tag-prefix-cond” operator. If there are no tagged messages, mutt will "eat" the rest of the macro to abort it's execution. Mutt will stop "eating" the macro when it encounters the “end-cond” operator; after this operator the rest of the macro will be executed as normal.

## 4. Using Hooks

A hook is a concept found in many other programs which allows you to execute arbitrary commands before performing some operation. For example, you may wish to tailor your configuration based upon which mailbox you are reading, or to whom you are sending mail. In the Mutt world, a hook consists of a regular expression or pattern along with a configuration option/command. See

- folder-hook

- send-hook

- message-hook

- save-hook

- mbox-hook

- fcc-hook

- fcc-save-hook

for specific details on each type of hook available.

### Note

If a hook changes configuration settings, these changes remain effective until the end of the current mutt session. As this is generally not desired, a default hook needs to be added before all other hooks to restore configuration defaults. Here is an example with send-hook and the my_hdr directive:

Example 4.2. Combining `send-hook` and `my_hdr`

    send-hook . 'unmy_hdr From:'
    send-hook ~C'^b@b\.b$' my_hdr from: c@c.c

### 4.1. Message Matching in Hooks

Hooks that act upon messages (`message-hook, reply-hook, send-hook, send2-hook, save-hook, fcc-hook`) are evaluated in a slightly different manner. For the other types of hooks, a regular expression is sufficient. But in dealing with messages a finer grain of control is needed for matching since for different purposes you want to match different criteria.

Mutt allows the use of the search pattern language for matching messages in hook commands. This works in exactly the same way as it would when limiting or searching the mailbox, except that you are restricted to those operators which match information mutt extracts from the header of the message (i.e., from, to, cc, date, subject, etc.).

For example, if you wanted to set your return address based upon sending mail to a specific address, you could do something like:

    send-hook '~t ^me@cs\.hmc\.edu$' 'my_hdr From: Mutt User <user@host>'

which would execute the given command when sending mail to me@cs.hmc.edu.

However, it is not required that you write the pattern to match using the full searching language. You can still specify a simple regular expression like the other hooks, in which case Mutt will translate your pattern into the full language, using the translation specified by the $default_hook variable. The pattern is translated at the time the hook is declared, so the value of $default_hook that is in effect at that time will be used.

## 5. External Address Queries

Mutt supports connecting to external directory databases such as LDAP, ph/qi, bbdb, or NIS through a wrapper script which connects to mutt using a simple interface. Using the $query_command variable, you specify the wrapper command to use. For example:

    set query_command = "mutt_ldap_query.pl '%s'"

The wrapper script should accept the query on the command-line. It should return a one line message, then each matching response on a single line, each line containing a tab separated address then name then some other optional information. On error, or if there are no matching addresses, return a non-zero exit code and a one line error message.

An example multiple response output:

    Searching database ... 20 entries ... 3 matching:
    me@cs.hmc.edu           Michael Elkins  mutt dude
    blong@fiction.net       Brandon Long    mutt and more
    roessler@does-not-exist.org        Thomas Roessler mutt pgp

There are two mechanisms for accessing the query function of mutt. One is to do a query from the index menu using the `<query>` function (default: Q). This will prompt for a query, then bring up the query menu which will list the matching responses. From the query menu, you can select addresses to create aliases, or to mail. You can tag multiple addresses to mail, start a new query, or have a new query appended to the current responses.

The other mechanism for accessing the query function is for address completion, similar to the alias completion. In any prompt for address entry, you can use the `<complete-query>` function (default: ^T) to run a query based on the current address you have typed. Like aliases, mutt will look for what you have typed back to the last space or comma. If there is a single response for that query, mutt will expand the address in place. If there are multiple responses, mutt will activate the query menu. At the query menu, you can select one or more addresses to be added to the prompt.

## 6. Mailbox Formats

Mutt supports reading and writing of four different mailbox formats: mbox, MMDF, MH and Maildir. The mailbox type is autodetected, so there is no need to use a flag for different mailbox types. When creating new mailboxes, Mutt uses the default specified with the $mbox_type variable.

mbox. This is the most widely used mailbox format for UNIX. All messages are stored in a single file. Each message has a line of the form:

    From me@cs.hmc.edu Fri, 11 Apr 1997 11:44:56 PST

to denote the start of a new message (this is often referred to as the “From_” line).

MMDF. This is a variant of the mbox format. Each message is surrounded by lines containing “^A^A^A^A” (four control-A's).

MH. A radical departure from mbox and MMDF, a mailbox consists of a directory and each message is stored in a separate file. The filename indicates the message number (however, this is may not correspond to the message number Mutt displays). Deleted messages are renamed with a comma (,) prepended to the filename. Mutt detects this type of mailbox by looking for either `.mh_sequences` or `.xmhcache` (needed to distinguish normal directories from MH mailboxes).

Maildir. The newest of the mailbox formats, used by the Qmail MTA (a replacement for sendmail). Similar to MH, except that it adds three subdirectories of the mailbox: tmp, new and cur. Filenames for the messages are chosen in such a way they are unique, even when two programs are writing the mailbox over NFS, which means that no file locking is needed.

## 7. Mailbox Shortcuts

There are a number of built in shortcuts which refer to specific mailboxes. These shortcuts can be used anywhere you are prompted for a file or mailbox path.

- ! -- refers to your $spoolfile (incoming) mailbox

- > -- refers to your $mbox file

- < -- refers to your $record file

- ^ -- refers to the current mailbox

- - or !! -- refers to the file you've last visited

- ˜ -- refers to your home directory

- = or + -- refers to your $folder directory

- @alias -- refers to the default save folder as determined by the address of the alias

## 8. Handling Mailing Lists

Mutt has a few configuration options that make dealing with large amounts of mail easier. The first thing you must do is to let Mutt know what addresses you consider to be mailing lists (technically this does not have to be a mailing list, but that is what it is most often used for), and what lists you are subscribed to. This is accomplished through the use of the lists and subscribe commands in your muttrc.

Now that Mutt knows what your mailing lists are, it can do several things, the first of which is the ability to show the name of a list through which you received a message (i.e., of a subscribed list) in the index menu display. This is useful to distinguish between personal and list mail in the same mailbox. In the $index_format variable, the escape “%L” will return the string “To <list>” when “list” appears in the “To” field, and “Cc <list>” when it appears in the “Cc” field (otherwise it returns the name of the author).

Often times the “To” and “Cc” fields in mailing list messages tend to get quite large. Most people do not bother to remove the author of the message they reply to from the list, resulting in two or more copies being sent to that person. The `<list-reply>` function, which by default is bound to “L” in the index menu and pager, helps reduce the clutter by only replying to the known mailing list addresses instead of all recipients (except as specified by `Mail-Followup-To`, see below).

Mutt also supports the `Mail-Followup-To` header. When you send a message to a list of recipients which includes one or several subscribed mailing lists, and if the $followup_to option is set, mutt will generate a Mail-Followup-To header which contains all the recipients to whom you send this message, but not your address. This indicates that group-replies or list-replies (also known as “followups”) to this message should only be sent to the original recipients of the message, and not separately to you - you'll receive your copy through one of the mailing lists you are subscribed to.

Conversely, when group-replying or list-replying to a message which has a `Mail-Followup-To` header, mutt will respect this header if the $honor_followup_to configuration variable is set. Using list-reply will in this case also make sure that the reply goes to the mailing list, even if it's not specified in the list of recipients in the `Mail-Followup-To`.

### Note

When header editing is enabled, you can create a `Mail-Followup-To` header manually. Mutt will only auto-generate this header if it doesn't exist when you send the message.

The other method some mailing list admins use is to generate a “Reply-To” field which points back to the mailing list address rather than the author of the message. This can create problems when trying to reply directly to the author in private, since most mail clients will automatically reply to the address given in the “Reply-To” field. Mutt uses the $reply_to variable to help decide which address to use. If set to ask-yes or ask-no, you will be prompted as to whether or not you would like to use the address given in the “Reply-To” field, or reply directly to the address given in the “From” field. When set to yes, the “Reply-To” field will be used when present.

The “X-Label:” header field can be used to further identify mailing lists or list subject matter (or just to annotate messages individually). The $index_format variable's “%y” and “%Y” escapes can be used to expand “X-Label:” fields in the index, and Mutt's pattern-matcher can match regular expressions to “X-Label:” fields with the “˜y” selector. “X-Label:” is not a standard message header field, but it can easily be inserted by procmail and other mail filtering agents.

Lastly, Mutt has the ability to sort the mailbox into threads. A thread is a group of messages which all relate to the same subject. This is usually organized into a tree-like structure where a message and all of its replies are represented graphically. If you've ever used a threaded news client, this is the same concept. It makes dealing with large volume mailing lists easier because you can easily delete uninteresting threads and quickly find topics of value.

## 9. Handling multiple folders

Mutt supports setups with multiple folders, allowing all of them to be monitored for new mail (see Section 14, “Monitoring incoming mail” for details).

When in the index menu and being idle (also see $timeout), Mutt periodically checks for new mail in all folders which have been configured via the `mailboxes` command. The interval depends on the folder type: for local/IMAP folders it consults $mail_check and $pop_checkinterval for POP folders.

Outside the index menu the directory browser supports checking for new mail using the `<check-new>` function which is unbound by default. Pressing TAB will bring up a menu showing the files specified by the `mailboxes` command, and indicate which contain new messages. Mutt will automatically enter this mode when invoked from the command line with the `-y` option.

For the pager, index and directory browser menus, Mutt contains the `<buffy-list>` function (bound to “.” by default) which will print a list of folders with new mail in the command line at the bottom of the screen.

For the index, by default Mutt displays the number of mailboxes with new mail in the status bar, please refer to the $index_format variable for details.

When changing folders, Mutt fills the prompt with the first folder from the mailboxes list containing new mail (if any), pressing space will cycle through folders with new mail.

## 10. Editing threads

Mutt has the ability to dynamically restructure threads that are broken either by misconfigured software or bad behavior from some correspondents. This allows to clean your mailboxes formats) from these annoyances which make it hard to follow a discussion.

### 10.1. Linking threads

Some mailers tend to "forget" to correctly set the "In-Reply-To:" and "References:" headers when replying to a message. This results in broken discussions because Mutt has not enough information to guess the correct threading. You can fix this by tagging the reply, then moving to the parent message and using the `<link-threads>` function (bound to & by default). The reply will then be connected to this "parent" message.

You can also connect multiple children at once, tagging them and using the tag-prefix command (';') or the auto_tag option.

### 10.2. Breaking threads

On mailing lists, some people are in the bad habit of starting a new discussion by hitting "reply" to any message from the list and changing the subject to a totally unrelated one. You can fix such threads by using the `<break-thread>` function (bound by default to #), which will turn the subthread starting from the current message into a whole different thread.

## 11. Delivery Status Notification (DSN) Support

RFC1894 defines a set of MIME content types for relaying information about the status of electronic mail messages. These can be thought of as “return receipts.”

To support DSN, there are two variables. $dsn_notify is used to request receipts for different results (such as failed message, message delivered, etc.). $dsn_return requests how much of your message should be returned with the receipt (headers or full message).

When using $sendmail for mail delivery, you need to use either Berkeley sendmail 8.8.x (or greater) a MTA supporting DSN command line options compatible to Sendmail: The -N and -R options can be used by the mail client to make requests as to what type of status messages should be returned. Please consider your MTA documentation whether DSN is supported.

For SMTP delivery using $smtp_url, it depends on the capabilities announced by the server whether mutt will attempt to request DSN or not.

## 12. Start a WWW Browser on URLs

If a message contains URLs, it is efficient to get a menu with all the URLs and start a WWW browser on one of them. This functionality is provided by the external urlview program which can be retrieved at ftp://ftp.mutt.org/mutt/contrib/ and the configuration commands:

    macro index \cb |urlview\n
    macro pager \cb |urlview\n

## Chapter 5. Mutt's MIME Support

Quite a bit of effort has been made to make Mutt the premier text-mode MIME MUA. Every effort has been made to provide the functionality that the discerning MIME user requires, and the conformance to the standards wherever possible. When configuring Mutt for MIME, there are two extra types of configuration files which Mutt uses. One is the `mime.types` file, which contains the mapping of file extensions to IANA MIME types. The other is the `mailcap` file, which specifies the external commands to use for handling specific MIME types.

## 1. Using MIME in Mutt

There are three areas/menus in Mutt which deal with MIME, they are the pager (while viewing a message), the attachment menu and the compose menu.

### 1.1. Viewing MIME messages in the pager

When you select a message from the index and view it in the pager, Mutt decodes the message to a text representation. Mutt internally supports a number of MIME types, including `text/plain, text/enriched, message/rfc822, and message/news`. In addition, the export controlled version of Mutt recognizes a variety of PGP MIME types, including PGP/MIME and application/pgp.

Mutt will denote attachments with a couple lines describing them. These lines are of the form:

    [-- Attachment #1: Description --]
    [-- Type: text/plain, Encoding: 7bit, Size: 10000 --]

Where the `Description` is the description or filename given for the attachment, and the `Encoding` is one of `7bit/8bit/quoted-printable/base64/binary`.

If Mutt cannot deal with a MIME type, it will display a message like:

    [-- image/gif is unsupported (use 'v' to view this part) --]

### 1.2. The Attachment Menu

The default binding for `view-attachments` is `v', which displays the attachment menu for a message. The attachment menu displays a list of the attachments in a message. From the attachment menu, you can save, print, pipe, delete, and view attachments. You can apply these operations to a group of attachments at once, by tagging the attachments and by using the “tag-prefix” operator. You can also reply to the current message from this menu, and only the current attachment (or the attachments tagged) will be quoted in your reply. You can view attachments as text, or view them using the mailcap viewer definition.

Finally, you can apply the usual message-related functions (like `<resend-message>`, and the `<reply>` and `<forward>` functions) to attachments of type `message/rfc822`.

See the help on the attachment menu for more information.

### 1.3. The Compose Menu

The compose menu is the menu you see before you send a message. It allows you to edit the recipient list, the subject, and other aspects of your message. It also contains a list of the attachments of your message, including the main body. From this menu, you can print, copy, filter, pipe, edit, compose, review, and rename an attachment or a list of tagged attachments. You can also modifying the attachment information, notably the type, encoding and description.

Attachments appear as follows:

    - 1 [text/plain, 7bit, 1K]           /tmp/mutt-euler-8082-0 <no description>
      2 [applica/x-gunzip, base64, 422K] ~/src/mutt-0.85.tar.gz <no description>

The '-' denotes that Mutt will delete the file after sending (or postponing, or canceling) the message. It can be toggled with the `toggle-unlink` command (default: u). The next field is the MIME content-type, and can be changed with the `edit-type` command (default: ^T). The next field is the encoding for the attachment, which allows a binary message to be encoded for transmission on 7bit links. It can be changed with the `edit-encoding` command (default: ^E). The next field is the size of the attachment, rounded to kilobytes or megabytes. The next field is the filename, which can be changed with the `rename-file` command (default: R). The final field is the description of the attachment, and can be changed with the `edit-description` command (default: d).

## 2. MIME Type configuration with `mime.types`

When you add an attachment to your mail message, Mutt searches your personal mime.types file at `${HOME}/.mime.types`, and then the system mime.types file at `/usr/local/share/mutt/mime.types` or `/etc/mime.types`

The mime.types file consist of lines containing a MIME type and a space separated list of extensions. For example:

    application/postscript          ps eps
    application/pgp                 pgp
    audio/x-aiff                    aif aifc aiff

A sample `mime.types` file comes with the Mutt distribution, and should contain most of the MIME types you are likely to use.

If Mutt can not determine the mime type by the extension of the file you attach, it will look at the file. If the file is free of binary information, Mutt will assume that the file is plain text, and mark it as `text/plain`. If the file contains binary information, then Mutt will mark it as `application/octet-stream`. You can change the MIME type that Mutt assigns to an attachment by using the `edit-type` command from the compose menu (default: ^T). The MIME type is actually a major mime type followed by the sub-type, separated by a '/'. 6 major types: application, text, image, video, audio, and model have been approved after various internet discussions. Mutt recognizes all of these if the appropriate entry is found in the mime.types file. It also recognizes other major mime types, such as the chemical type that is widely used in the molecular modeling community to pass molecular data in various forms to various molecular viewers. Non-recognized mime types should only be used if the recipient of the message is likely to be expecting such attachments.

## 3. MIME Viewer configuration with `mailcap`

Mutt supports RFC 1524 MIME Configuration, in particular the Unix specific format specified in Appendix A of RFC 1524. This file format is commonly referred to as the mailcap format. Many MIME compliant programs utilize the mailcap format, allowing you to specify handling for all MIME types in one place for all programs. Programs known to use this format include Netscape, XMosaic, lynx and metamail.

In order to handle various MIME types that Mutt can not handle internally, Mutt parses a series of external configuration files to find an external handler. The default search string for these files is a colon delimited list containing the following files:

1. `$HOME/.mailcap`

2. `$PKGDATADIR/mailcap`

3. `$SYSCONFDIR/mailcap`

4. `/etc/mailcap`

5. `/usr/etc/mailcap`

6. `/usr/local/etc/mailcap`

where `$HOME` is your home directory. The `$PKGDATADIR` and the `$SYSCONFDIR` directories depend on where mutt is installed: the former is the default for shared data, the latter for system configuration files.

The default search path can be obtained by running the following command:

    mutt -nF /dev/null -Q mailcap_path

In particular, the metamail distribution will install a mailcap file, usually as `/usr/local/etc/mailcap`, which contains some baseline entries.

### 3.1. The Basics of the mailcap file

A mailcap file consists of a series of lines which are comments, blank, or definitions.

A comment line consists of a # character followed by anything you want.

A blank line is blank.

A definition line consists of a content type, a view command, and any number of optional fields. Each field of a definition line is divided by a semicolon ';' character.

The content type is specified in the MIME standard type/subtype method. For example, `text/plain, text/html, image/gif,` etc. In addition, the mailcap format includes two formats for wildcards, one using the special '*' subtype, the other is the implicit wild, where you only include the major type. For example, `image/*`, or `video,` will match all image types and video types, respectively.

The view command is a Unix command for viewing the type specified. There are two different types of commands supported. The default is to send the body of the MIME message to the command on stdin. You can change this behavior by using %s as a parameter to your view command. This will cause Mutt to save the body of the MIME message to a temporary file, and then call the view command with the %s replaced by the name of the temporary file. In both cases, Mutt will turn over the terminal to the view program until the program quits, at which time Mutt will remove the temporary file if it exists.

So, in the simplest form, you can send a text/plain message to the external pager more on stdin:

    text/plain; more

Or, you could send the message as a file:

    text/plain; more %s

Perhaps you would like to use lynx to interactively view a text/html message:

    text/html; lynx %s

In this case, lynx does not support viewing a file from stdin, so you must use the %s syntax.

### Note

Some older versions of lynx contain a bug where they will check the mailcap file for a viewer for text/html. They will find the line which calls lynx, and run it. This causes lynx to continuously spawn itself to view the object.

On the other hand, maybe you don't want to use lynx interactively, you just want to have it convert the text/html to text/plain, then you can use:

    text/html; lynx -dump %s | more

Perhaps you wish to use lynx to view text/html files, and a pager on all other text formats, then you would use the following:

    text/html; lynx %s
    text/*; more

This is the simplest form of a mailcap file.

### 3.2. Secure use of mailcap

The interpretation of shell meta-characters embedded in MIME parameters can lead to security problems in general. Mutt tries to quote parameters in expansion of %s syntaxes properly, and avoids risky characters by substituting them, see the $mailcap_sanitize variable.

Although mutt's procedures to invoke programs with mailcap seem to be safe, there are other applications parsing mailcap, maybe taking less care of it. Therefore you should pay attention to the following rules:

Keep the %-expandos away from shell quoting. Don't quote them with single or double quotes. Mutt does this for you, the right way, as should any other program which interprets mailcap. Don't put them into backtick expansions. Be highly careful with eval statements, and avoid them if possible at all. Trying to fix broken behavior with quotes introduces new leaks - there is no alternative to correct quoting in the first place.

If you have to use the %-expandos' values in context where you need quoting or backtick expansions, put that value into a shell variable and reference the shell variable where necessary, as in the following example (using `$charset` inside the backtick expansion is safe, since it is not itself subject to any further expansion):

    text/test-mailcap-bug; cat %s; copiousoutput; test=charset=%{charset} \
            && test "`echo $charset | tr '[A-Z]' '[a-z]'`" != iso-8859-1

### 3.3. Advanced mailcap Usage

#### 3.3.1. Optional Fields

In addition to the required content-type and view command fields, you can add semi-colon ';' separated fields to set flags and other options. Mutt recognizes the following optional fields:

copiousoutput

  This flag tells Mutt that the command passes possibly large amounts of text on stdout. This causes Mutt to invoke a pager (either the internal pager or the external pager defined by the pager variable) on the output of the view command. Without this flag, Mutt assumes that the command is interactive. One could use this to replace the pipe to `more` in the `lynx -dump` example in the Basic section:

      text/html; lynx -dump %s ; copiousoutput

  This will cause lynx to format the text/html output as text/plain and Mutt will use your standard pager to display the results.

needsterminal

  Mutt uses this flag when viewing attachments with auto_view, in order to decide whether it should honor the setting of the $wait_key variable or not. When an attachment is viewed using an interactive program, and the corresponding mailcap entry has a needsterminal flag, Mutt will use $wait_key and the exit status of the program to decide if it will ask you to press a key after the external program has exited. In all other situations it will not prompt you for a key.

compose=<command>

  This flag specifies the command to use to create a new attachment of a specific MIME type. Mutt supports this from the compose menu.

composetyped=<command>

  This flag specifies the command to use to create a new attachment of a specific MIME type. This command differs from the compose command in that mutt will expect standard MIME headers on the data. This can be used to specify parameters, filename, description, etc. for a new attachment. Mutt supports this from the compose menu.

print=<command>

  This flag specifies the command to use to print a specific MIME type. Mutt supports this from the attachment and compose menus.

edit=<command>

  This flag specifies the command to use to edit a specific MIME type. Mutt supports this from the compose menu, and also uses it to compose new attachments. Mutt will default to the defined editor for text attachments.

nametemplate=<template>

  This field specifies the format for the file denoted by %s in the command fields. Certain programs will require a certain file extension, for instance, to correctly view a file. For instance, lynx will only interpret a file as `text/html` if the file ends in `.html`. So, you would specify lynx as a `text/html` viewer with a line in the mailcap file like:

      text/html; lynx %s; nametemplate=%s.html

test=<command>

  This field specifies a command to run to test whether this mailcap entry should be used. The command is defined with the command expansion rules defined in the next section. If the command returns 0, then the test passed, and Mutt uses this entry. If the command returns non-zero, then the test failed, and Mutt continues searching for the right entry. Note that the content-type must match before Mutt performs the test. For example:

      text/html; netscape -remote 'openURL(%s)' ; test=RunningX
      text/html; lynx %s

  In this example, Mutt will run the program RunningX which will return 0 if the X Window manager is running, and non-zero if it isn't. If RunningX returns 0, then Mutt will call netscape to display the text/html object. If RunningX doesn't return 0, then Mutt will go on to the next entry and use lynx to display the text/html object.

#### 3.3.2. Search Order

When searching for an entry in the mailcap file, Mutt will search for the most useful entry for its purpose. For instance, if you are attempting to print an `image/gif`, and you have the following entries in your mailcap file, Mutt will search for an entry with the print command:

    image/*;        xv %s
    image/gif;      ; print= anytopnm %s | pnmtops | lpr; \
                    nametemplate=%s.gif

Mutt will skip the `image/*` entry and use the `image/gif` entry with the print command.

In addition, you can use this with auto_view to denote two commands for viewing an attachment, one to be viewed automatically, the other to be viewed interactively from the attachment menu. In addition, you can then use the test feature to determine which viewer to use interactively depending on your environment.

    text/html;      netscape -remote 'openURL(%s)' ; test=RunningX
    text/html;      lynx %s; nametemplate=%s.html
    text/html;      lynx -dump %s; nametemplate=%s.html; copiousoutput

For auto_view, Mutt will choose the third entry because of the copiousoutput tag. For interactive viewing, Mutt will run the program RunningX to determine if it should use the first entry. If the program returns non-zero, Mutt will use the second entry for interactive viewing.

#### 3.3.3. Command Expansion

The various commands defined in the mailcap files are passed to the `/bin/sh` shell using the system() function. Before the command is passed to `/bin/sh -c`, it is parsed to expand various special parameters with information from Mutt. The keywords Mutt expands are:

%s

  As seen in the basic mailcap section, this variable is expanded to a filename specified by the calling program. This file contains the body of the message to view/print/edit or where the composing program should place the results of composition. In addition, the use of this keyword causes Mutt to not pass the body of the message to the view/print/edit program on stdin.

%t

  Mutt will expand %t to the text representation of the content type of the message in the same form as the first parameter of the mailcap definition line, ie `text/html` or `image/gif`.

%{<parameter>}

  Mutt will expand this to the value of the specified parameter from the Content-Type: line of the mail message. For instance, if Your mail message contains:

      Content-Type: text/plain; charset=iso-8859-1

  then Mutt will expand %{charset} to iso-8859-1. The default metamail mailcap file uses this feature to test the charset to spawn an xterm using the right charset to view the message.

\%

  This will be replaced by a %

Mutt does not currently support the %F and %n keywords specified in RFC 1524. The main purpose of these parameters is for multipart messages, which is handled internally by Mutt.

### 3.4. Example mailcap files

This mailcap file is fairly simple and standard:

    # I'm always running X :)
    video/*;        xanim %s > /dev/null
    image/*;        xv %s > /dev/null

    # I'm always running netscape (if my computer had more memory, maybe)
    text/html;      netscape -remote 'openURL(%s)'

This mailcap file shows quite a number of examples:

    # Use xanim to view all videos   Xanim produces a header on startup,
    # send that to /dev/null so I don't see it
    video/*;        xanim %s > /dev/null

    # Send html to a running netscape by remote
    text/html;      netscape -remote 'openURL(%s)'; test=RunningNetscape

    # If I'm not running netscape but I am running X, start netscape on the
    # object
    text/html;      netscape %s; test=RunningX

    # Else use lynx to view it as text
    text/html;      lynx %s

    # This version would convert the text/html to text/plain
    text/html;      lynx -dump %s; copiousoutput

    # I use enscript to print text in two columns to a page
    text/*;         more %s; print=enscript -2Gr %s

    # Netscape adds a flag to tell itself to view jpegs internally
    image/jpeg;xv %s; x-mozilla-flags=internal

    # Use xv to view images if I'm running X
    # In addition, this uses the \ to extend the line and set my editor
    # for images
    image/*;xv %s; test=RunningX; \
            edit=xpaint %s

    # Convert images to text using the netpbm tools
    image/*;  (anytopnm %s | pnmscale -xysize 80 46 | ppmtopgm | pgmtopbm |
    pbmtoascii -1x2 ) 2>&1 ; copiousoutput

    # Send excel spreadsheets to my NT box
    application/ms-excel; open.pl %s

## 4. MIME Autoview

In addition to explicitly telling Mutt to view an attachment with the MIME viewer defined in the mailcap file, Mutt has support for automatically viewing MIME attachments while in the pager.

To work, you must define a viewer in the mailcap file which uses the `copiousoutput` option to denote that it is non-interactive. Usually, you also use the entry to convert the attachment to a text representation which you can view in the pager.

You then use the `auto_view` muttrc command to list the content-types that you wish to view automatically.

For instance, if you set auto_view to:

    auto_view text/html application/x-gunzip \
      application/postscript image/gif application/x-tar-gz

Mutt could use the following mailcap entries to automatically view attachments of these types.

    text/html;      lynx -dump %s; copiousoutput; nametemplate=%s.html
    image/*;        anytopnm %s | pnmscale -xsize 80 -ysize 50 | ppmtopgm | \
                    pgmtopbm | pbmtoascii ; copiousoutput
    application/x-gunzip;   gzcat; copiousoutput
    application/x-tar-gz; gunzip -c %s | tar -tf - ; copiousoutput
    application/postscript; ps2ascii %s; copiousoutput

“unauto_view” can be used to remove previous entries from the autoview list. This can be used with message-hook to autoview messages based on size, etc. “unauto_view *” will remove all previous entries.

## 5. MIME Multipart/Alternative

Mutt has some heuristics for determining which attachment of a multipart/alternative type to display. First, mutt will check the alternative_order list to determine if one of the available types is preferred. The alternative_order list consists of a number of mimetypes in order, including support for implicit and explicit wildcards, for example:

    alternative_order text/enriched text/plain text application/postscript image/*

Next, mutt will check if any of the types have a defined auto_view, and use that. Failing that, Mutt will look for any text type. As a last attempt, mutt will look for any type it knows how to handle.

To remove a MIME type from the `alternative_order` list, use the `unalternative_order` command.

## 6. Attachment Searching and Counting

If you ever lose track of attachments in your mailboxes, Mutt's attachment-counting and -searching support might be for you. You can make your message index display the number of qualifying attachments in each message, or search for messages by attachment count. You also can configure what kinds of attachments qualify for this feature with the attachments and unattachments commands.

In order to provide this information, mutt needs to fully MIME-parse all messages affected first. This can slow down operation especially for remote mail folders such as IMAP because all messages have to be downloaded first regardless whether the user really wants to view them or not.

The syntax is:

    attachments   {+|-}disposition mime-type
    unattachments {+|-}disposition mime-type
    attachments   ?

Disposition is the attachment's Content-disposition type -- either `inline` or `attachment`. You can abbreviate this to `I` or `A`.

Disposition is prefixed by either a + symbol or a - symbol. If it's a +, you're saying that you want to allow this disposition and MIME type to qualify. If it's a -, you're saying that this disposition and MIME type is an exception to previous + rules. There are examples below of how this is useful.

Mime-type is, unsurprisingly, the MIME type of the attachment you want to affect. A MIME type is always of the format `major/minor`, where `major` describes the broad category of document you're looking at, and `minor` describes the specific type within that category. The major part of mime-type must be literal text (or the special token “`*`”), but the minor part may be a regular expression. (Therefore, “`*/.*`” matches any MIME type.)

The MIME types you give to the attachments directive are a kind of pattern. When you use the attachments directive, the patterns you specify are added to a list. When you use unattachments, the pattern is removed from the list. The patterns are not expanded and matched to specific MIME types at this time -- they're just text in a list. They're only matched when actually evaluating a message.

Some examples might help to illustrate. The examples that are not commented out define the default configuration of the lists.

Example 5.1. Attachment counting

    ## Removing a pattern from a list removes that pattern literally. It
    ## does not remove any type matching the pattern.
    ##
    ##  attachments   +A */.*
    ##  attachments   +A image/jpeg
    ##  unattachments +A */.*
    ##
    ## This leaves "attached" image/jpeg files on the allowed attachments
    ## list. It does not remove all items, as you might expect, because the
    ## second */.* is not a matching expression at this time.
    ##
    ## Remember: "unattachments" only undoes what "attachments" has done!
    ## It does not trigger any matching on actual messages.

    ## Qualify any MIME part with an "attachment" disposition, EXCEPT for
    ## text/x-vcard and application/pgp parts. (PGP parts are already known
    ## to mutt, and can be searched for with ~g, ~G, and ~k.)
    ##
    ## I've added x-pkcs7 to this, since it functions (for S/MIME)
    ## analogously to PGP signature attachments. S/MIME isn't supported
    ## in a stock mutt build, but we can still treat it specially here.
    ##
    attachments   +A */.*
    attachments   -A text/x-vcard application/pgp.*
    attachments   -A application/x-pkcs7-.*

    ## Discount all MIME parts with an "inline" disposition, unless they're
    ## text/plain. (Why inline a text/plain part unless it's external to the
    ## message flow?)
    ##
    attachments   +I text/plain

    ## These two lines make Mutt qualify MIME containers.  (So, for example,
    ## a message/rfc822 forward will count as an attachment.)  The first
    ## line is unnecessary if you already have "attach-allow */.*", of
    ## course.  These are off by default!  The MIME elements contained
    ## within a message/* or multipart/* are still examined, even if the
    ## containers themseves don't qualify.
    ##
    #attachments  +A message/.* multipart/.*
    #attachments  +I message/.* multipart/.*

    ## You probably don't really care to know about deleted attachments.
    attachments   -A message/external-body
    attachments   -I message/external-body

Entering the command “`attachments ?`” as a command will list your current settings in Muttrc format, so that it can be pasted elsewhere.

## 7. MIME Lookup

Mutt's mime_lookup list specifies a list of mime-types that should not be treated according to their mailcap entry. This option is designed to deal with binary types such as application/octet-stream. When an attachment's mime-type is listed in mime_lookup, then the extension of the filename will be compared to the list of extensions in the mime.types file. The mime-type associated with this extension will then be used to process the attachment according to the rules in the mailcap file and according to any other configuration options (such as auto_view) specified. Common usage would be:

    mime_lookup application/octet-stream application/X-Lotus-Manuscript

In addition, the unmime_lookup command may be used to disable this feature for any particular mime-type if it had been set, for example, in a global muttrc.

## Chapter 6. Optional features

## 1. General notes

### 1.1. Enabling/disabling features

Mutt supports several of optional features which can be enabled or disabled at compile-time by giving the configure script certain arguments. These are listed in the “Optional features” section of the configure --help output.

Which features are enabled or disabled can later be determined from the output of `mutt -v`. If a compile option starts with “+” it is enabled and disabled if prefixed with “-”. For example, if mutt was compiled using GnuTLS for encrypted communication instead of OpenSSL, `mutt -v` would contain:

    -USE_SSL_OPENSSL +USE_SSL_GNUTLS

### 1.2. URL syntax

Mutt optionally supports the IMAP, POP3 and SMTP protocols which require to access servers using URLs. The canonical syntax for specifying URLs in mutt is (an item enclosed in `[]` means it is optional and may be omitted):

    proto[s]://[username[:password]@]server[:port]/[path]

`proto` is the communication protocol: `imap` for IMAP, `pop` for POP3 and `smtp` for SMTP. If “s” for “secure communication” is appended, mutt will attempt to establish an encrypted communication using SSL or TLS. If no explicit port is given, mutt will use the system's default for the given protocol.

Since all protocols by mutt support authentication, the username may be given directly in the URL instead of using the `pop_user` or `imap_user` variables. It may contain the “@” symbol being used by many mail systems as part of the login name. A password can be given, too but is not recommended if the URL is specified in a configuration file on disk.

The optional path is only relevant for IMAP.

For IMAP for example, you can select an alternative port by specifying it with the server: `imap://imapserver:port/INBOX`. You can also specify different username for each folder: `imap://username@imapserver[:port]/INBOX` or `imap://username2@imapserver[:port]/path/to/folder`. Replacing `imap://` by `imaps://` would make mutt attempt to connect using SSL or TLS on a different port to encrypt the communication.

## 2. SSL/TLS Support

If mutt is compiled with IMAP, POP3 and/or SMTP support, it can also be compiled with support for SSL or TLS using either OpenSSL or GnuTLS ( by running the configure script with the --enable-ssl=... option for OpenSSL or --enable-gnutls=... for GnuTLS). Mutt can then attempt to encrypt communication with remote servers if these protocols are suffixed with “s” for “secure communication”.

## 3. POP3 Support

If Mutt was compiled with POP3 support (by running the configure script with the --enable-pop flag), it has the ability to work with mailboxes located on a remote POP3 server and fetch mail for local browsing.

Remote POP3 servers can be accessed using URLs with the `pop` protocol for unencrypted and `pops` for encrypted communication, see Section 1.2, “URL syntax” for details.

Polling for new mail is more expensive over POP3 than locally. For this reason the frequency at which Mutt will check for mail remotely can be controlled by the $pop_checkinterval variable, which defaults to every 60 seconds.

Another way to access your POP3 mail is the `<fetch-mail$` function (default: G). It allows to connect to $pop_host, fetch all your new mail and place it in the local $spoolfile. After this point, Mutt runs exactly as if the mail had always been local.

### Note

If you only need to fetch all messages to a local mailbox you should consider using a specialized program, such as `fetchmail`, `getmail` or similar.

## 4. IMAP Support

If Mutt was compiled with IMAP support (by running the configure script with the --enable-imap flag), it has the ability to work with folders located on a remote IMAP server.

You can access the remote inbox by selecting the folder by its URL (see Section 1.2, “URL syntax” for details) using the `imap` or `imaps` protocol. Alternatively, a pine-compatible notation is also supported, ie `{[username@]imapserver[:port][/ssl]}path/to/folder`

Note that not all servers use “/” as the hierarchy separator. Mutt should correctly notice which separator is being used by the server and convert paths accordingly.

When browsing folders on an IMAP server, you can toggle whether to look at only the folders you are subscribed to, or all folders with the toggle-subscribed command. See also the $imap_list_subscribed variable.

Polling for new mail on an IMAP server can cause noticeable delays. So, you'll want to carefully tune the $mail_check and $timeout variables. Personally I use

    set mail_check=90
    set timeout=15

with relatively good results over my slow modem line.

### Note

Note that if you are using mbox as the mail store on UW servers prior to v12.250, the server has been reported to disconnect a client if another client selects the same folder.

### 4.1. The Folder Browser

As of version 1.2, mutt supports browsing mailboxes on an IMAP server. This is mostly the same as the local file browser, with the following differences:

- In lieu of file permissions, mutt displays the string "IMAP", possibly followed by the symbol "+", indicating that the entry contains both messages and subfolders. On Cyrus-like servers folders will often contain both messages and subfolders.

- For the case where an entry can contain both messages and subfolders, the selection key (bound to `enter` by default) will choose to descend into the subfolder view. If you wish to view the messages in that folder, you must use `view-file` instead (bound to `space` by default).

- You can create, delete and rename mailboxes with the `create-mailbox`, `delete-mailbox`, and `rename-mailbox` commands (default bindings: `C`, `d` and `r`, respectively). You may also `subscribe` and `unsubscribe` to mailboxes (normally these are bound to `s` and `u`, respectively).

### 4.2. Authentication

Mutt supports four authentication methods with IMAP servers: SASL, GSSAPI, CRAM-MD5, and LOGIN (there is a patch by Grant Edwards to add NTLM authentication for you poor exchange users out there, but it has yet to be integrated into the main tree). There is also support for the pseudo-protocol ANONYMOUS, which allows you to log in to a public IMAP server without having an account. To use ANONYMOUS, simply make your username blank or "anonymous".

SASL is a special super-authenticator, which selects among several protocols (including GSSAPI, CRAM-MD5, ANONYMOUS, and DIGEST-MD5) the most secure method available on your host and the server. Using some of these methods (including DIGEST-MD5 and possibly GSSAPI), your entire session will be encrypted and invisible to those teeming network snoops. It is the best option if you have it. To use it, you must have the Cyrus SASL library installed on your system and compile mutt with the --with-sasl flag.

Mutt will try whichever methods are compiled in and available on the server, in the following order: SASL, ANONYMOUS, GSSAPI, CRAM-MD5, LOGIN.

There are a few variables which control authentication:

- $imap_user - controls the username under which you request authentication on the IMAP server, for all authenticators. This is overridden by an explicit username in the mailbox path (ie by using a mailbox name of the form `{user@host}`).

- $imap_pass - a password which you may preset, used by all authentication methods where a password is needed.

- $imap_authenticators - a colon-delimited list of IMAP authentication methods to try, in the order you wish to try them. If specified, this overrides mutt's default (attempt everything, in the order listed above).

## 5. SMTP Support

Besides supporting traditional mail delivery through a sendmail-compatible program, mutt supports delivery through SMTP if it was configured and built with `--enable-smtp`.

If the configuration variable $smtp_url is set, mutt will contact the given SMTP server to deliver messages; if it is unset, mutt will use the program specified by $sendmail.

For details on the URL syntax, please see Section 1.2, “URL syntax”.

The built-in SMTP support supports encryption (the `smtps` protocol using SSL or TLS) as well as SMTP authentication using SASL. The authentication mechanisms for SASL are specified in $smtp_authenticators defaulting to an empty list which makes mutt try all available methods from most-secure to least-secure.

## 6. Managing multiple accounts

If you happen to have accounts on multiple IMAP, POP and/or SMTP servers, you may find managing all the authentication settings inconvenient and error-prone. The account-hook command may help. This hook works like folder-hook but is invoked whenever you access a remote mailbox (including inside the folder browser), not just when you open the mailbox which includes (for example) polling for new mail, storing Fcc messages and saving messages to a folder. As a consequence, account-hook should only be used to set connection-related settings such as passwords or tunnel commands but not settings such as sender address or name (because in general it should be considered unpredictable which account-hook was last used).

Some examples:

    account-hook . 'unset imap_user; unset imap_pass; unset tunnel'
    account-hook imap://host1/ 'set imap_user=me1 imap_pass=foo'
    account-hook imap://host2/ 'set tunnel="ssh host2 /usr/libexec/imapd"'
    account-hook smtp://user@host3/ 'set tunnel="ssh host3 /usr/libexec/smtpd"'

## 7. Local caching

Mutt contains two types of local caching: (1) the so-called “header caching” and (2) the so-called “body caching” which are both described in this section.

Header caching is optional as it depends on external libraries, body caching is always enabled if mutt is compiled with POP and/or IMAP support as these use it (body caching requires no external library).

### 7.1. Header caching

Mutt provides optional support for caching message headers for the following types of folders: IMAP, POP, Maildir and MH. Header caching greatly improves speed because for remote folders, headers usually only need to be downloaded once. For Maildir and MH, reading the headers from a single file is much faster than looking at possibly thousands of single files (since Maildir and MH use one file per message.)

Header caching can be enabled via the configure script and the --enable-hcache option. It's not turned on by default because external database libraries are required: one of tokyocabinet, qdbm, gdbm or bdb must be present.

If enabled, $header_cache can be used to either point to a file or a directory. If set to point to a file, one database file for all folders will be used (which may result in lower performance), but one file per folder if it points to a directory.

For the one-file-per-folder case, database files for remote folders will be named according to their URL while database files for local folders will be named by the MD5 checksums of their path. These database files may be safely removed if a system is short on space. You can compute the name of the header cache file for a particular local folder through a command like the following:

    $ printf '%s' '/path/to/folder' | md5sum

The `md5sum` command may also be named `md5`, depending on your operating system.

### 7.2. Body caching

Both cache methods can be combined using the same directory for storage (and for IMAP/POP even provide meaningful file names) which simplifies manual maintenance tasks.

In addition to caching message headers only, mutt can also cache whole message bodies. This results in faster display of messages for POP and IMAP folders because messages usually have to be downloaded only once.

For configuration, the variable $message_cachedir must point to a directory. There, mutt will create a hierarchy of subdirectories named like: `proto:user@hostname` where `proto` is either “pop” or “imap.” Within there for each folder, mutt stores messages in single files (just like Maildir) so that with manual symlink creation these cache directories can be examined with mutt as read-only Maildir folders.

All files can be removed as needed if the consumed disk space becomes an issue as mutt will silently fetch missing items again.

### 7.3. Maintenance

Mutt does not (yet) support maintenance features for header cache database files so that files have to be removed in case they grow too big. It depends on the database library used for header caching whether disk space freed by removing messages is re-used.

For body caches, mutt can keep the local cache in sync with the remote mailbox if the $message_cache_clean variable is set. Cleaning means to remove messages from the cache which are no longer present in the mailbox which only happens when other mail clients or instances of mutt using a different body cache location delete messages (Mutt itself removes deleted messages from the cache when syncing a mailbox). As cleaning can take a noticeable amount of time, it should not be set in general but only occasionally.

## 8. Exact address generation

Mutt supports the “Name <user@host>” address syntax for reading and writing messages, the older “user@host (Name)” syntax is only supported when reading messages. The --enable-exact-address switch can be given to configure to build it with write-support for the latter syntax. `EXACT_ADDRESS` in the output of `mutt -v` indicates whether it's supported.

## Chapter 7. Performance tuning

## 1. Reading and writing mailboxes

Mutt's performance when reading mailboxes can be improved in two ways:

1. For remote folders (IMAP and POP) as well as folders using one-file-per message storage (Maildir and MH), mutt's performance can be greatly improved using header caching. Using a single database per folder may further increase performance.

2. Mutt provides the $read_inc and $write_inc variables to specify at which rate to update progress counters. If these values are too low, mutt may spend more time on updating the progress counter than it spends on actually reading/writing folders.

   For example, when opening a maildir folder with a few thousand messages, the default value for $read_inc may be too low. It can be tuned on on a folder-basis using folder-hooks:

       # use very high $read_inc to speed up reading hcache'd maildirs
       folder-hook . 'set read_inc=1000'
       # use lower value for reading slower remote IMAP folders
       folder-hook ^imap 'set read_inc=100'
       # use even lower value for reading even slower remote POP folders
       folder-hook ^pop 'set read_inc=1'

These settings work on a per-message basis. However, as messages may greatly differ in size and certain operations are much faster than others, even per-folder settings of the increment variables may not be desirable as they produce either too few or too much progress updates. Thus, Mutt allows to limit the number of progress updates per second it'll actually send to the terminal using the $time_inc variable.

## 2. Reading messages from remote folders

Reading messages from remote folders such as IMAP an POP can be slow especially for large mailboxes since mutt only caches a very limited number of recently viewed messages (usually 10) per session (so that it will be gone for the next session.)

To improve performance and permanently cache whole messages, please refer to mutt's so-called body caching for details.

## 3. Searching and limiting

When searching mailboxes either via a search or a limit action, for some patterns mutt distinguishes between regular expression and string searches. For regular expressions, patterns are prefixed with “˜” and with “=” for string searches.

Even though a regular expression search is fast, it's several times slower than a pure string search which is noticeable especially on large folders. As a consequence, a string search should be used instead of a regular expression search if the user already knows enough about the search pattern.

For example, when limiting a large folder to all messages sent to or by an author, it's much faster to search for the initial part of an e-mail address via `=Luser@` instead of `˜Luser@`. This is especially true for searching message bodies since a larger amount of input has to be searched.

Please note that string search is an exact case-sensitive search while a regular expression search with only lower-case letters performs a case-insensitive search.

## Chapter 8. Reference

## 1. Command line options

Running `mutt` with no arguments will make Mutt attempt to read your spool mailbox. However, it is possible to read other mailboxes and to send messages from the command line as well.

Table 8.1. Command line options

Option | Description
--- | ---
-A | expand an alias
-a | attach a file to a message
-b | specify a blind carbon-copy (BCC) address
-c | specify a carbon-copy (Cc) address
-D | print the value of all mutt variables to stdout
-e | specify a config command to be run after initialization files are read
-f | specify a mailbox to load
-F | specify an alternate file to read initialization commands
-h | print help on command line options
-H | specify a draft file from which to read a header and body
-i | specify a file to include in a message composition
-m | specify a default mailbox type
-n | do not read the system Muttrc
-p | recall a postponed message
-Q | query a configuration variable
-R | open mailbox in read-only mode
-s | specify a subject (enclose in quotes if it contains spaces)
-v | show version number and compile-time definitions
-x | simulate the mailx(1) compose mode
-y | show a menu containing the files specified by the mailboxes command
-z | exit immediately if there are no messages in the mailbox
-Z | open the first folder with new message,exit immediately if none

To read messages in a mailbox

`mutt` [`-nz`] [`-F` `muttrc` ] [`-m` `type` ] [`-f` `mailbox` ]

To compose a new message

`mutt` [`-n`] [`-F` `muttrc` ] [`-a` `file` ] [`-c` `address` ] [`-i` `filename` ] [`-s` `subject` ] [ [ `file` ...] -- ] `address` [ `address` ...]

Mutt also supports a “batch” mode to send prepared messages. Simply redirect input from the file you wish to send. For example,

`mutt -s "data set for run #2" professor@bigschool.edu < ˜/run2.dat`

This command will send a message to “professor@bigschool.edu” with a subject of “data set for run #2”. In the body of the message will be the contents of the file “˜/run2.dat”.

All files passed with -a file will be attached as a MIME part to the message. To attach several files, use “--” to separate files and recipient addresses: `mutt -a *.png -- some@one.org`

## 2. Configuration Commands

The following are the commands understood by mutt.

- `account-hook` `pattern` `command`

- `alias` [ `-group` `name` ...] `key` `address` [ `address` ...]

- `unalias` [ `-group` `name` ...] { `*` | `key` ... }

- `alternates` [ `-group` `name` ...] `regexp` [ `regexp` ...]

- `unalternates` [ `-group` `name` ...] { `*` | `regexp` ... }

- `alternative-order` `mimetype` [ `mimetype` ...]

- `unalternative-order` { `*` | `mimetype` ... }

- `auto-view` `mimetype` [ `mimetype` ...]

- `unauto-view` { `*` | `mimetype` ... }

- `bind` `map` `key` `function`

- `charset-hook` `alias` `charset`

- `iconv-hook` `charset` `local-charset`

- `color` `object` `foreground` `background`

  `color` { `header` | `body` } `foreground` `background` `regexp`

  `color` `index` `foreground` `background` `pattern`

- `uncolor` `index` `pattern` ...

- `exec` `function` [ `function` ...]

- `fcc-hook` `[!]pattern` `mailbox`

- `fcc-save-hook` `[!]pattern` `mailbox`

- `folder-hook` `[!]regexp` `command`

- `group` [ `-group` `name` ...] { `-rx` `expr` ... | `-addr` `expr` ... }

- `ungroup` [ `-group` `name` ...] { `*` | `-rx` `expr` ... | `-addr` `expr` ... }

- `hdr_order` `header` [ `header` ...]

- `unhdr_order` { `*` | `header` ... }

- `ignore` `pattern` [ `pattern` ...]

- `unignore` { `*` | `pattern` ... }

- `lists` [ `-group` `name` ] `regexp` [ `regexp` ...]

- `unlists` [ `-group` `name` ...] { `*` | `regexp` ... }

- `macro` `menu` `key` `sequence` [ `description` ]

- `mailboxes` `mailbox` [ `mailbox` ...]

- `unmailboxes` { `*` | `mailbox` ... }

- `mbox-hook` `[!]pattern` `mailbox`

- `message-hook` `[!]pattern` `command`

- `mime-lookup` `mimetype` [ `mimetype` ...]

- `unmime-lookup` { `*` | `mimetype` ... }

- `mono` `object` `attribute`

  `mono` { `header` | `body` } `attribute` `regexp`

  `mono` `index` `attribute` `pattern`

- `unmono` `index` { `*` | `pattern` ... }

- `my_hdr` `string`

- `unmy_hdr` { `*` | `field` ... }

- `crypt-hook` `pattern` `keyid`

- `push` `string`

- `reset` `variable` [ `variable` ...]

- `save-hook` `[!]pattern` `mailbox`

- `score` `pattern` `value`

- `unscore` { `*` | `pattern` ... }

- `reply-hook` `[!]pattern` `command`

- `send-hook` `[!]pattern` `command`

- `send2-hook` `[!]pattern` `command`

- `set` { [ `no` | `inv` ] `variable` | `variable=value` } [...]

- `unset` `variable` [ `variable` ...]

- `source` `filename`

- `spam` `pattern` `format`

- `nospam` { `*` | `pattern` }

- `subscribe` [ `-group` `name` ...] `regexp` [ `regexp` ...]

- `unsubscribe` [ `-group` `name` ...] { `*` | `regexp` ... }

- `toggle` `variable` [ `variable` ...]

- `unhook` { `*` | `hook-type` }

## 3. Configuration variables

## 4. Functions

The following is the list of available functions listed by the mapping in which they are available. The default key setting is given, and an explanation of what the function does. The key bindings of these functions can be changed with the bind command.

## Chapter 9. Miscellany

## 1. Acknowledgements

Kari Hurtta `<kari.hurtta@fmi.fi>` co-developed the original MIME parsing code back in the ELM-ME days.

The following people have been very helpful to the development of Mutt:

- Vikas Agnihotri `<vikasa@writeme.com>`

- Francois Berjon `<Francois.Berjon@aar.alcatel-alsthom.fr>`

- Aric Blumer `<aric@fore.com>`

- John Capo `<jc@irbs.com>`

- David Champion `<dgc@uchicago.edu>`

- Brendan Cully `<brendan@kublai.com>`

- Liviu Daia `<daia@stoilow.imar.ro>`

- Thomas E. Dickey `<dickey@herndon4.his.com>`

- David DeSimone `<fox@convex.hp.com>`

- Nickolay N. Dudorov `<nnd@wint.itfs.nsk.su>`

- Ruslan Ermilov `<ru@freebsd.org>`

- Edmund Grimley Evans `<edmundo@rano.org>`

- Michael Finken `<finken@conware.de>`

- Sven Guckes `<guckes@math.fu-berlin.de>`

- Lars Hecking `<lhecking@nmrc.ie>`

- Mark Holloman `<holloman@nando.net>`

- Andreas Holzmann `<holzmann@fmi.uni-passau.de>`

- Marco d'Itri `<md@linux.it>`

- Björn Jacke `<bjacke@suse.com>`

- Byrial Jensen `<byrial@image.dk>`

- David Jeske `<jeske@igcom.net>`

- Christophe Kalt `<kalt@hugo.int-evry.fr>`

- Tommi Komulainen `<Tommi.Komulainen@iki.fi>`

- Felix von Leitner (a.k.a “Fefe”) `<leitner@math.fu-berlin.de>`

- Brandon Long `<blong@fiction.net>`

- Jimmy Mäkelä `<jmy@flashback.net>`

- Lars Marowsky-Bree `<lmb@pointer.in-minden.de>`

- Thomas “Mike” Michlmayr `<mike@cosy.sbg.ac.at>`

- Andrew W. Nosenko `<awn@bcs.zp.ua>`

- David O'Brien `<obrien@Nuxi.cs.ucdavis.edu>`

- Clint Olsen `<olsenc@ichips.intel.com>`

- Park Myeong Seok `<pms@romance.kaist.ac.kr>`

- Thomas Parmelan `<tom@ankh.fr.eu.org>`

- Ollivier Robert `<roberto@keltia.freenix.fr>`

- Thomas Roessler `<roessler@does-not-exist.org>`

- Roland Rosenfeld `<roland@spinnaker.de>`

- Rocco Rutte `<pdmef@gmx.net>`

- TAKIZAWA Takashi `<taki@luna.email.ne.jp>`

- Allain Thivillon `<Allain.Thivillon@alma.fr>`

- Gero Treuner `<gero@70t.de>`

- Vsevolod Volkov `<vvv@lucky.net>`

- Ken Weinert `<kenw@ihs.com>`

## 2. About this document

This document was written in DocBook, and then rendered using the Gnome XSLT toolkit.