Table of Contents
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.
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.
Mutt is configured through variables which, if the user wants to permanently use a non-default value, are written to configuration files. Mutt supports a rich config file syntax to make even complex configuration files readable and commentable.
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 behavior including managing multiple identities, customizing the display for a folder or even implementing auto-archiving based on a per-folder basis and much more.
Besides an interactive mode, Mutt can also be used as a command-line
tool to send messages. It also supports a
mailx(1)-compatible interface, see Table 9.1, “Command line options” for a complete list of command-line
options.
The index is the screen that you usually see first when you start Mutt. It gives an overview over your emails in the currently opened mailbox. By default, this is your system mailbox. The information you see in the index is a list of emails, each with its number on the left, its flags (new email, important email, email that has been forwarded or replied to, tagged email, ...), the date when email was sent, its sender, the email size, and the subject. Additionally, the index also shows thread hierarchies: when you reply to an email, and the other person replies back, you can see the other person's email in a "sub-tree" below. This is especially useful for personal email between a group of people or when you've subscribed to mailing lists.
The pager is responsible for showing the email content. On the top of the pager you have an overview over the most important email headers like the sender, the recipient, the subject, and much more information. How much information you actually see depends on your configuration, which we'll describe below.
Below the headers, you see the email body which usually contains the message. If the email contains any attachments, you will see more information about them below the email body, or, if the attachments are text files, you can view them directly in the pager.
To give the user a good overview, it is possible to configure Mutt to show different things in the pager with different colors. Virtually everything that can be described with a regular expression can be colored, e.g. URLs, email addresses or smileys.
The file browser is the interface to the local or remote file system. When selecting a mailbox to open, the browser allows custom sorting of items, limiting the items shown by a regular expression and a freely adjustable format of what to display in which way. It also allows for easy navigation through the file system when selecting file(s) to attach to a message, select multiple files to attach and many more.
Some mail systems can nest mail folders inside other mail folders.
The normal open entry commands in mutt will open the mail folder and
you can't see the sub-folders. If you instead use the
<descend-directory> function it will go into
the directory and not open it as a mail directory.
The Sidebar shows a list of all your mailboxes. The list can be turned on and off, it can be themed and the list style can be configured.
The help screen is meant to offer a quick help to the user. It lists the current configuration of key bindings and their associated commands including a short description, and currently unbound functions that still need to be associated with a key binding (or alternatively, they can be called via the Mutt command prompt).
The compose menu features a split screen containing the information which really matter before actually sending a message by mail: who gets the message as what (recipients and who gets what kind of copy). Additionally, users may set security options like deciding whether to sign, encrypt or sign and encrypt a message with/for what keys. Also, it's used to attach messages, to re-edit any attachment including the message itself.
The alias menu is used to help users finding the recipients of messages. For users who need to contact many people, there's no need to remember addresses or names completely because it allows for searching, too. The alias mechanism and thus the alias menu also features grouping several addresses by a shorter nickname, the actual alias, so that users don't have to select each single recipient manually.
As will be later discussed in detail, Mutt features a good and stable MIME implementation, that is, it supports sending and receiving messages of arbitrary MIME types. The attachment menu displays a message's structure in detail: what content parts are attached to which parent part (which gives a true tree structure), which type is of what type and what size. Single parts may saved, deleted or modified to offer great and easy access to message's internals.
The most important navigation keys common to line- or entry-based menus are shown in Table 2.1, “Most common navigation keys in entry-based menus” and in Table 2.2, “Most common navigation keys in page-based menus” for page-based menus.
Table 2.1. Most common navigation keys in entry-based menus
| 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 |
Table 2.2. Most common navigation keys in page-based menus
| Key | Function | Description |
|---|---|---|
| J or <Return> | <next-line> | scroll down one line |
| <Backspace> | <previous-line> | scroll up one line |
| K, <Space> or <PageDn> | <next-page> | move to the next page |
| - or <PageUp> | <previous-page> | move the previous page |
| <Home> | <top> | move to the top |
| <End> | <bottom> | move to the bottom |
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 2.3, “Most common line editor keys” for a full reference of available functions, their default key bindings, and short descriptions.
Table 2.3. 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, alias, or label |
| ^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 |
| ^R | <history-search> | use current input to search 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 |
^G is the generic “abort” key
in Mutt. In addition to the line editor, it can also be used
to abort prompts. Generally, typing ^G at a
confirmation prompt or line editor should abort the entire action.
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
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 and $save_history. You may cycle through them
at an editor prompt by using the <history-up>
and/or <history-down> commands. Mutt will
remember the currently entered text as you cycle through history, and
will wrap around to the initial entry line.
Mutt maintains several distinct history lists, one for each of the following categories:
.muttrc commands
addresses and aliases
shell commands
filenames
mailboxes
patterns
everything else
Mutt automatically filters out consecutively repeated items from the history. If $history_remove_dups is set, all repeated items are removed 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.
Similar to many other mail clients, there are two modes in which mail is read in Mutt. The first is a list of messages in the mailbox, which is called the “index” menu 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.
Common keys used to navigate through and manage messages in the index are shown in Table 2.4, “Most common message index keys”. How messages are presented in the index menu can be customized using the $index_format variable.
Table 2.4. 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 2.5, “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 2.6, “Message recipient flags” reflect who the message is addressed to. They can be customized with the $to_chars variable.
Table 2.5. 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 |
| n | thread contains new messages (only if collapsed) |
| o | thread contains old messages (only if collapsed) |
Table 2.6. 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 |
By default, Mutt uses its built-in pager to display the contents of
messages (an external pager such as less(1) can be
configured, see $pager variable). The
pager is very similar to the Unix program less(1)
though not nearly as featureful.
Table 2.7. 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 2.7, “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 2.8, “ANSI escape sequences”.
Table 2.8. 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 2.9, “Color sequences”) |
| 4<color> | Background color is <color> (see Table 2.9, “Color sequences”) |
Mutt uses these attributes for handling text/enriched
messages, and they can also be used by an external autoview script for highlighting purposes.
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 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 patterns are used to select messages by criteria whereas the pager already displays a selected message.
So-called “threads” provide a hierarchy of messages where replies are linked to their parent message(s). This organizational form is extremely useful in mailing lists where different parts of the discussion diverge. Mutt displays threads as a tree structure.
In Mutt, when a mailbox is sorted by threads, there are a few additional functions available in the index and pager modes as shown in Table 2.10, “Most common thread mode keys”.
Table 2.10. 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 |
In the index, the subject of threaded children messages will be prepended with thread tree characters. By default, the subject itself will not be duplicated unless $hide_thread_subject is unset. Special characters will be added to the thread tree as detailed in Table 2.11, “Special Thread Characters”.
Table 2.11. Special Thread Characters
| Character | Description | Notes |
|---|---|---|
| & | hidden message | see $hide_limited and $hide_top_limited |
| ? | missing message | see $hide_missing and $hide_top_missing |
| * | pseudo thread | see $strict_threads; not displayed when $narrow_tree is set |
| = | duplicate thread | see $duplicate_threads; not displayed when $narrow_tree is set |
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. The
%?<char>?<if-part>&<else-part>?
syntax is explained in detail in format string conditionals.
Technically, every reply should contain a list of its parent messages in the thread tree, but not all do. In these cases, Mutt groups them by subject which can be controlled using the $strict_threads variable.
In addition, the index and pager menus have these interesting functions:
<check-stats>
Calculate statistics for all monitored mailboxes declared using the mailboxes command. It will calculate statistics despite $mail_check_stats being unset.
<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
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. In addition, the List-Post header field is
examined for mailto: URLs specifying a mailing list address.
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_decode_weed, $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.
The bindings shown in Table 2.12, “Most common mail sending keys” are available in the index and pager to start a new message.
Table 2.12. Most common mail sending keys
| Key | Function | Description |
|---|---|---|
| m | <mail> | compose a new message |
| r | <reply> | reply to sender |
| g | <group-reply> | reply to all recipients |
<group-chat-reply> | reply to all recipients preserving To/Cc | |
| 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 section “Forwarding and Bouncing Mail.”
Mutt will then enter the compose menu and prompt
you for the recipients to place on the “To:” header field
when you hit m to start a new message. Next, it will
ask you for the “Subject:” field for the message, providing
a default if you are replying to or forwarding a message. You again have
the chance to adjust recipients, subject, and security settings right
before actually sending the message. See also $askcc, $askbcc,
$autoedit, $bounce, $fast_reply, and $include for changing how and if Mutt asks
these questions.
When replying, Mutt fills these fields with proper values depending on the reply type. The types of replying supported are:
Reply to the author directly.
Reply to the author; cc all other recipients; consults alternates and excludes you.
Reply to the author and other recipients in the To list; cc other recipients in the Cc list; consults alternates and excludes you.
Reply to all mailing list addresses found, either specified via configuration or auto-detected. See Section 14, “Mailing Lists” for details.
After getting recipients for new messages, forwards or replies, 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; the message body should start on a new line after the existing blank line at the end of headers. 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 2.13, “Most common compose menu keys” to modify, send or postpone the message.
Table 2.13. 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 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.
After exiting the compose menu via <send-message>,
the message will be sent. If configured and enabled, this can happen via
mixmaster or
$smtp_url. Otherwise
$sendmail will be invoked. Prior to
version 1.13, Mutt enabled $write_bcc by
default, assuming the MTA would automatically remove a
Bcc: header as part of delivery. Starting with 1.13, the
option is unset by default, but no longer affects the fcc copy of the message.
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 but trigger special Mutt behavior.
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. It can later be changed from the
compose menu.
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. Spaces in filenames have to be escaped using backslash (“\”). The file can be removed as well as more added from the compose menu.
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 for the duration of the message composition session. The selection can later be changed in the compose menu.
When replying to messages, the In-Reply-To: header contains the Message-Id of the message(s) you reply to. If you remove or modify 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.
If you intend to start a new thread by replying, please make really sure you remove the In-Reply-To: header in your editor. Otherwise, though you'll produce a technically valid reply, some netiquette guardians will be annoyed by this so-called “thread hijacking”.
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.
To ensure you can view encrypted messages you have sent, you may wish to set $pgp_self_encrypt and $pgp_default_key for PGP, or $smime_self_encrypt and $smime_default_key for S/MIME.
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 2.14, “PGP key menu flags”.
Table 2.14. 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.
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.
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, Mutt properly space-stuffs 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
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.
All leading spaces are to be removed by receiving clients to restore the original message prior to further processing.
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.
For example, vim provides the w
flag for its formatoptions setting to assist in
creating f=f messages, see :help
fo-table for details.
Mutt has some support for reformatting when viewing and replying to
format=flowed messages. In order to take advantage of these,
$reflow_text must be set.
Paragraphs are automatically reflowed and wrapped at a width specified by $reflow_wrap.
In its original format, the quoting style of format=flowed
messages can be difficult to read, and doesn't intermix well with
non-flowed replies.
Setting $reflow_space_quotes
adds spaces after each level of quoting when in the pager and
replying in a non-flowed format
(i.e. with $text_flowed unset).
If $reflow_space_quotes is unset, mutt will still add one trailing space after all the quotes in the pager (but not when replying).
If $editor is set to a graphical editor, or a script such as contrib/bgedit-screen-tmux.sh if running inside GNU Screen or tmux, you can run the editor in the background by setting $background_edit.
If set, Mutt will display a landing page while the editor runs.
When the editor exits, message composition will resume
automatically. Alternatively, you can
<exit> from the landing page, which will
return you to the message index. This allows viewing other
messages, changing mailboxes, even starting a new message
composition session - all while the first editor session is still
running.
Backgrounded message composition sessions can be viewed via
<background-compose-menu> in the index and
pager, by default bound to “B”. If
there is only a single backgrounded session, which has already
exited, that session will automatically resume. Otherwise the list
will be displayed, and a particular session can be selected. $background_format controls the
format string used for the menu.
In case the open mailbox is changed while a reply is backgrounded, Mutt keeps track of the original mailbox. After sending, Mutt will attempt to reopen the original mailbox, if needed, and set reply flags appropriately. This won't affect your currently open mailbox, but may make setting flags a bit slower due to the need to reopen the original mailbox behind the scenes.
One complication with backgrounded compose sessions is the config changes caused by send, reply, and folder hooks. These can get triggered by a new message composition session, or by changing folders during a backgrounded session. To help lessen these problems, Mutt takes a snapshot of certain configuration variables and stores them with each editing session when it is backgrounded. When the session is resumed, those stored settings will temporarily be restored, and removed again when the session finishes (or is backgrounded again).
Mutt will save all boolean and
quadoption configuration variables, along with
$folder,
$record,
$postponed,
$envelope_from_address,
$from,
$sendmail,
$smtp_url,
$pgp_sign_as,
$smime_sign_as, and
$smime_encrypt_with.
It's not feasible to backup all variables, but if you believe
we've missed an important setting, please let the developers know.
To help prevent forgetting about backgrounded sessions, $background_confirm_quit
will prompt before exiting, in addition to $quit. Additionally, the %B
expando in $status_format
displays the number of backgrounded compose sessions.
Background editing is available for most, but not all, message composition in Mutt. Sending from the command line disables background editing, because there is no index to return to.
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 $mime_forward is a quadoption which, for example, can be set to “ask-no”.
Mutt's default ($mime_forward=“no” and $forward_decode=“yes”) is to use standard inline forwarding. In that mode all text-decodable parts are included in the new message body. Other attachments from the original email can also be attached to the new message, based on the quadoption $forward_attachments.
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, but can be disabled via the quadoption $forward_edit.
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.
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.
OpenPGP and S/MIME are enabled in one of two ways: “classic mode” or GPGME. The former invokes external programs to perform the various operations; it is better tested and more flexible, but requires some configuration. The latter uses the GnuPG project's GPGME library.
To enable “classic mode”, ensure GPGME is disabled and
use the gpg.rc or smime.rc files
that come with mutt. These are typically installed under
/usr/local/share/doc/mutt/samples/. Source them, either
directly or by copying them to your .mutt directory and sourcing them.
Sourcing them directly from
/usr/local/share/doc/mutt/samples/ has the benefit of
automatically using fixes and security improvements to the command
invocations, and is recommended.
unset crypt_use_gpgme source /usr/local/share/doc/mutt/samples/gpg.rc source /usr/local/share/doc/mutt/samples/smime.rc
To use GPGME instead, simply ensure the option is enabled in your .muttrc:
set crypt_use_gpgme
The two most important settings are $pgp_default_key and $pgp_sign_as. To perform encryption, you must set the first variable. If you have a separate signing key, or only have a signing key, then set the second. Most people will only need to set $pgp_default_key.
Starting with version 2.1.0, GnuPG automatically uses an
agent to prompt for your passphrase. If you are
using a version older than that, you'll need to ensure an agent is
running (alternatively, you can unset $pgp_use_gpg_agent and Mutt will
prompt you for your passphrase). The agent in turn uses a
pinentry program to display the prompt. There are
many different kinds of pinentry programs that can be used: qt, gtk2,
gnome3, fltk, and curses. However, Mutt does not
work properly with the tty pinentry program. Please ensure you have
one of the GUI or curses pinentry programs installed and configured to
be the default for your system.
As with OpenPGP, the two most important settings are $smime_default_key and $smime_sign_as. To perform encryption and decryption, you must set the first variable. If you have a separate signing key, or only have a signing key, then set the second. Most people will only need to set $smime_default_key.
In “classic mode”, keys and certificates are managed by
the smime_keys program that comes with Mutt. By
default they are stored under ~/.smime/. (This is
set by the smime.rc file with $smime_certificates and $smime_keys.) To initialize this
directory, use the command “smime_keys
init” from a shell prompt. The program can be then
be used to import and list certificates. You may also want to
periodically run “smime_keys refresh”
to update status flags for your certificates.