X-Git-Url: https://git.llucax.com/software/mutt-debian.git/blobdiff_plain/14c29200cb58d3c4a0830265f2433849781858d0..c71aaa5c83036e5b1685f66887d51832b6fb49f7:/doc/optionalfeatures.html?ds=sidebyside diff --git a/doc/optionalfeatures.html b/doc/optionalfeatures.html index 1647c82..0547002 100644 --- a/doc/optionalfeatures.html +++ b/doc/optionalfeatures.html @@ -1,296 +1,390 @@ -Chapter 6. Optional features

Chapter 6. Optional features

Table of Contents

1. General notes
1.1. Enabling/disabling features
1.2. URL syntax
2. SSL/TLS Support
3. POP3 Support
4. IMAP Support
4.1. The Folder Browser
4.2. Authentication
5. SMTP Support
6. Managing multiple accounts
7. Local caching
7.1. Header caching
7.2. Body caching
7.3. Maintenance
8. Exact address generation

1. General notes

1.1. Enabling/disabling features

+Chapter 6. Optional Features

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. +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: +“+” 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

+-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): +in Mutt is (an item enclosed in [] means it is +optional and may be omitted):

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

-proto is the communication protocol: +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. +smtp for SMTP. If “s” for “secure +communication” is appended, Mutt will attempt to establish an +encrypted communication using SSL or TLS. +

+Since all protocols supported by Mutt support/require authentication, +login credentials may be specified in the URL. This has the advantage +that multiple IMAP, POP3 or SMTP servers may be specified (which isn't +possible using, for example, $imap_user). The username may contain the +“@” symbol being used by many mail systems as part of the +login name. The special characters “/” +(%2F), “:” (%3A) and +“%” (%25) have to be URL-encoded in +usernames using the %-notation.

-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. A password can be given, too but -is not recommended if the URL is specified in a configuration file on -disk. +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. +If no port number is given, Mutt will use the system's default for the +given protocol (usually consulting /etc/services).

-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 conect 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 +The optional path is only relevant for IMAP and ignored elsewhere. +

Example 6.1. URLs

+pops://host/
+imaps://user@host/INBOX/Sent
+smtp://user@host:587/
+

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 +are suffixed with “s” for “secure +communication”. +

3. POP3 Support

+If Mutt is 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. +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. +controlled by the $pop_checkinterval variable, which +defaults to every 60 seconds.

-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 +POP is read-only which doesn't allow for some features like editing +messages or changing flags. However, using Section 7.1, “Header Caching” and Section 7.2, “Body Caching” Mutt +simulates the new/old/read flags as well as flagged and replied. Mutt +applies some logic on top of remote messages but cannot change them so +that modifications of flags are lost when messages are downloaded from +the POP server (either by Mutt or other tools). +

+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(1), getmail(1) 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 +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 +Alternatively, a pine-compatible notation is also supported, i.e. {[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. +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. +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 - +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. Reasonable values are:

 set mail_check=90
 set timeout=15
 

- -with relatively good results over my slow modem line. -

+with relatively good results even over slow modem lines. +

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 +v12.250, the server has been reported to disconnect a client if another +client selects the same folder. +

4.1. The IMAP 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 +

    • +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). -

    • +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

+<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". +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. +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. +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 +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 (i.e. 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

+

  • +$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 +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. +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”. +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. +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

    +Usage: +

    account-hook +pattern + +command +

    +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 Mutt needs to access a remote mailbox (including inside +the folder browser), not just when you open the mailbox. This 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"'
     

    +To manage multiple accounts with, for example, different values of $record or sender addresses, folder-hook has to be be +used together with the mailboxes command. +

    Example 6.2. Managing multiple accounts

    +mailboxes imap://user@host1/INBOX
    +folder-hook imap://user@host1/ 'set folder=imap://host1/ ; set record=+INBOX/Sent'
     
    -

    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. +mailboxes imap://user@host2/INBOX +folder-hook imap://user@host2/ 'set folder=imap://host2/ ; set record=+INBOX/Sent' +


    +In example Example 6.2, “Managing multiple accounts” the folders are defined +using mailboxes so +Mutt polls them for new mail. Each folder-hook triggers +when one mailbox below each IMAP account is opened and sets $folder to the account's root folder. Next, it +sets $record to the +INBOX/Sent folder below the newly set $folder. Please notice that the value the +“+” mailbox shortcut +refers to depends on the current value of $folder and therefore has to be set separately +per account. Setting other values like $from +or $signature is analogous to setting +$record. +

    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 +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

    +

    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.) +greatly speeds up opening large folders 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 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
    -

    +--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.

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

    7.2. Body caching

    +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. +

    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. +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 +For configuration, the variable $message_cachedir must point to a directory. There, Mutt will +create a hierarchy of subdirectories named like the account and mailbox +path the cache is for. +

    7.3. Cache Directories

    +For using both, header and body caching, $header_cache and $message_cachedir can be safely set +to the same value. +

    +In a header or body cache directory, Mutt creates a directory hierarchy 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. +proto is either “pop” or +“imap.” Within there, for each folder, Mutt stores messages +in single files and header caches in files with the +“.hcache” extension. All files can be removed as needed if +the consumed disk space becomes an issue as Mutt will silently fetch +missing items again. Pathnames are always stored in UTF-8 encoding.

    -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

    +For Maildir and MH, the header cache files are named after the MD5 +checksum of the path. +

    7.4. 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. -

    +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. +

    9. 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 or later. +

    +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. +