1 ## Dovecot configuration file
3 # If you're in a hurry, see http://wiki.dovecot.org/QuickConfiguration
5 # "dovecot -n" command gives a clean output of the changed settings. Use it
6 # instead of copy&pasting this file when posting to the Dovecot mailing list.
8 # '#' character and everything after it is treated as comments. Extra spaces
9 # and tabs are ignored. If you want to use either of these explicitly, put the
10 # value inside quotes, eg.: key = "# char and trailing whitespace "
12 # Default values are shown for each setting, it's not required to uncomment
13 # any of the lines. Exception to this are paths, they're just examples with
14 # the real defaults being based on configure options. The paths listed here
15 # are for configure --prefix=/usr --sysconfdir=/etc --localstatedir=/var
16 # --with-ssldir=/etc/ssl
18 # Base directory where to store runtime data.
19 #base_dir = /var/run/dovecot/
21 # Protocols we want to be serving: imap imaps pop3 pop3s managesieve
22 # If you only want to use dovecot-auth, you can set this to "none".
23 #protocols = imap imaps
25 # A space separated list of IP or host addresses where to listen in for
26 # connections. "*" listens in all IPv4 interfaces. "[::]" listens in all IPv6
27 # interfaces. Use "*, [::]" for listening both IPv4 and IPv6.
29 # If you want to specify ports for each service, you will need to configure
30 # these settings inside the protocol imap/pop3/managesieve { ... } section,
31 # so you can specify different ports for IMAP/POP3/MANAGESIEVE. For example:
34 # ssl_listen = *:10943
41 # protocol managesieve {
47 # Disable LOGIN command and all other plaintext authentications unless
48 # SSL/TLS is used (LOGINDISABLED capability). Note that if the remote IP
49 # matches the local IP (ie. you're connecting from the same computer), the
50 # connection is considered secure and plaintext authentication is allowed.
51 #disable_plaintext_auth = yes
53 # Should all IMAP and POP3 processes be killed when Dovecot master process
54 # shuts down. Setting this to "no" means that Dovecot can be upgraded without
55 # forcing existing client connections to close (although that could also be
56 # a problem if the upgrade is eg. because of a security fix). This however
57 # means that after master process has died, the client processes can't write
58 # to log files anymore.
59 #shutdown_clients = yes
65 # Log file to use for error messages, instead of sending them to syslog.
66 # /dev/stderr can be used to log into stderr.
69 # Log file to use for informational and debug messages.
70 # Default is the same as log_path.
73 # Prefix for each line written to log file. % codes are in strftime(3)
75 #log_timestamp = "%b %d %H:%M:%S "
77 # Syslog facility to use if you're logging to syslog. Usually if you don't
78 # want to use "mail", you'll use local0..local7. Also other standard
79 # facilities are supported.
80 #syslog_facility = mail
86 # IP or host address where to listen in for SSL connections. Remember to also
87 # add imaps and/or pop3s to protocols setting. Defaults to same as "listen"
88 # setting if not specified.
91 # SSL/TLS support: yes, no, required. <doc/wiki/SSL>
94 # PEM encoded X.509 SSL/TLS certificate and private key. They're opened before
95 # dropping root privileges, so keep the key file unreadable by anyone but
96 # root. Included doc/mkcert.sh can be used to easily generate self-signed
97 # certificate, just make sure to update the domains in dovecot-openssl.cnf
98 #ssl_cert_file = /etc/ssl/certs/dovecot.pem
99 #ssl_key_file = /etc/ssl/private/dovecot.pem
101 # If key file is password protected, give the password here. Alternatively
102 # give it when starting dovecot with -p parameter. Since this file is often
103 # world-readable, you may want to place this setting instead to a different
104 # root owned 0600 file by using !include_try <path>.
107 # File containing trusted SSL certificate authorities. Set this only if you
108 # intend to use ssl_verify_client_cert=yes. The CAfile should contain the
109 # CA-certificate(s) followed by the matching CRL(s).
112 # Request client to send a certificate. If you also want to require it, set
113 # ssl_require_client_cert=yes in auth section.
114 #ssl_verify_client_cert = no
116 # Which field from certificate to use for username. commonName and
117 # x500UniqueIdentifier are the usual choices. You'll also need to set
118 # ssl_username_from_cert=yes.
119 #ssl_cert_username_field = commonName
121 # How often to regenerate the SSL parameters file. Generation is quite CPU
122 # intensive operation. The value is in hours, 0 disables regeneration
124 #ssl_parameters_regenerate = 168
127 #ssl_cipher_list = ALL:!LOW:!SSLv2
129 # Show protocol level SSL errors.
136 # <doc/wiki/LoginProcess.txt>
138 # Directory where authentication process places authentication UNIX sockets
139 # which login needs to be able to connect to. The sockets are created when
140 # running as root, so you don't have to worry about permissions. Note that
141 # everything in this directory is deleted when Dovecot is started.
142 #login_dir = /var/run/dovecot/login
144 # chroot login process to the login_dir. Only reason not to do this is if you
145 # wish to run the whole Dovecot without roots. <doc/wiki/Rootless.txt>
148 # User to use for the login process. Create a completely new user for this,
149 # and don't use it anywhere else. The user must also belong to a group where
150 # only it has access, it's used to control access for authentication process.
151 # Note that this user is NOT used to access mails. <doc/wiki/UserIds.txt>
152 #login_user = dovecot
154 # Set max. process size in megabytes. If you don't use
155 # login_process_per_connection you might need to grow this.
156 #login_process_size = 64
158 # Should each login be processed in it's own process (yes), or should one
159 # login process be allowed to process multiple connections (no)? Yes is more
160 # secure, espcially with SSL/TLS enabled. No is faster since there's no need
161 # to create processes all the time.
162 #login_process_per_connection = yes
164 # Number of login processes to keep for listening new connections.
165 #login_processes_count = 3
167 # Maximum number of login processes to create. The listening process count
168 # usually stays at login_processes_count, but when multiple users start logging
169 # in at the same time more extra processes are created. To prevent fork-bombing
170 # we check only once in a second if new processes should be created - if all
171 # of them are used at the time, we double their amount until the limit set by
172 # this setting is reached.
173 #login_max_processes_count = 128
175 # Maximum number of connections allowed per each login process. This setting
176 # is used only if login_process_per_connection=no. Once the limit is reached,
177 # the process notifies master so that it can create a new login process.
178 #login_max_connections = 256
180 # Greeting message for clients.
181 #login_greeting = Dovecot ready.
183 # Space separated list of trusted network ranges. Connections from these
184 # IPs are allowed to override their IP addresses and ports (for logging and
185 # for authentication checks). disable_plaintext_auth is also ignored for
186 # these networks. Typically you'd specify your IMAP proxy servers here.
187 #login_trusted_networks =
189 # Space-separated list of elements we want to log. The elements which have
190 # a non-empty variable value are joined together to form a comma-separated
192 #login_log_format_elements = user=<%u> method=%m rip=%r lip=%l %c
194 # Login log format. %$ contains login_log_format_elements string, %s contains
195 # the data we want to log.
196 #login_log_format = %$: %s
199 ## Mailbox locations and namespaces
202 # Location for users' mailboxes. This is the same as the old default_mail_env
203 # setting. The default is empty, which means that Dovecot tries to find the
204 # mailboxes automatically. This won't work if the user doesn't have any mail
205 # yet, so you should explicitly tell Dovecot the full location.
207 # If you're using mbox, giving a path to the INBOX file (eg. /var/mail/%u)
208 # isn't enough. You'll also need to tell Dovecot where the other mailboxes are
209 # kept. This is called the "root mail directory", and it must be the first
210 # path given in the mail_location setting.
212 # There are a few special variables you can use, eg.:
215 # %n - user part in user@domain, same as %u if there's no domain
216 # %d - domain part in user@domain, empty if there's no domain
217 # %h - home directory
219 # See doc/wiki/Variables.txt for full list. Some examples:
221 # mail_location = maildir:~/Maildir
222 # mail_location = mbox:~/mail:INBOX=/var/mail/%u
223 # mail_location = mbox:/var/mail/%d/%1n/%n:INDEX=/var/indexes/%d/%1n/%n
225 # <doc/wiki/MailLocation.txt>
229 # If you need to set multiple mailbox locations or want to change default
230 # namespace settings, you can do it by defining namespace sections.
232 # You can have private, shared and public namespaces. Private namespaces
233 # are for user's personal mails. Shared namespaces are for accessing other
234 # users' mailboxes that have been shared. Public namespaces are for shared
235 # mailboxes that are managed by sysadmin. If you create any shared or public
236 # namespaces you'll typically want to enable ACL plugin also, otherwise all
237 # users can access all the shared mailboxes, assuming they have permissions
238 # on filesystem level to do so.
240 # REMEMBER: If you add any namespaces, the default namespace must be added
241 # explicitly, ie. mail_location does nothing unless you have a namespace
242 # without a location setting. Default namespace is simply done by having a
243 # namespace with empty prefix.
245 # Hierarchy separator to use. You should use the same separator for all
246 # namespaces or some clients get confused. '/' is usually a good one.
247 # The default however depends on the underlying mail storage format.
250 # Prefix required to access this namespace. This needs to be different for
251 # all namespaces. For example "Public/".
254 # Physical location of the mailbox. This is in same format as
255 # mail_location, which is also the default for it.
258 # There can be only one INBOX, and this setting defines which namespace
262 # If namespace is hidden, it's not advertised to clients via NAMESPACE
263 # extension. You'll most likely also want to set list=no. This is mostly
264 # useful when converting from another server with different namespaces which
265 # you want to deprecate but still keep working. For example you can create
266 # hidden namespaces with prefixes "~/mail/", "~%u/mail/" and "mail/".
269 # Show the mailboxes under this namespace with LIST command. This makes the
270 # namespace visible for clients that don't support NAMESPACE extension.
271 # "children" value lists child mailboxes, but hides the namespace prefix.
274 # Namespace handles its own subscriptions. If set to "no", the parent
275 # namespace handles them (empty prefix should always have this as "yes")
279 # Example shared namespace configuration
283 # Mailboxes are visible under "shared/user@domain/"
284 # %%n, %%d and %%u are expanded to the destination user.
285 #prefix = shared/%%u/
287 # Mail location for other users' mailboxes. Note that %variables and ~/
288 # expands to the logged in user's data. %%n, %%d, %%u and %%h expand to the
289 # destination user's data.
290 #location = maildir:%%h/Maildir:INDEX=~/Maildir/shared/%%u
292 # Use the default namespace for saving subscriptions.
295 # List the shared/ namespace only if there are visible shared mailboxes.
299 # System user and group used to access mails. If you use multiple, userdb
300 # can override these by returning uid or gid fields. You can use either numbers
301 # or names. <doc/wiki/UserIds>
305 # Group to enable temporarily for privileged operations. Currently this is
306 # used only with INBOX when either its initial creation or dotlocking fails.
307 # Typically this is set to "mail" to give access to /var/mail.
308 #mail_privileged_group =
310 # Grant access to these supplementary groups for mail processes. Typically
311 # these are used to set up access to shared mailboxes. Note that it may be
312 # dangerous to set these if users can create symlinks (e.g. if "mail" group is
313 # set here, ln -s /var/mail ~/mail/var could allow a user to delete others'
314 # mailboxes, or ln -s /secret/shared/box ~/mail/mybox would allow reading it).
315 #mail_access_groups =
317 # Allow full filesystem access to clients. There's no access checks other than
318 # what the operating system does for the active UID/GID. It works with both
319 # maildir and mboxes, allowing you to prefix mailboxes names with eg. /path/
321 #mail_full_filesystem_access = no
327 # Enable mail process debugging. This can help you figure out why Dovecot
328 # isn't finding your mails.
331 # Log prefix for mail processes. See doc/wiki/Variables.txt for list of
332 # possible variables you can use.
333 #mail_log_prefix = "%Us(%u): "
335 # Max. number of lines a mail process is allowed to log per second before it's
336 # throttled. 0 means unlimited. Typically there's no need to change this
337 # unless you're using mail_log plugin, which may log a lot. This setting is
338 # ignored while mail_debug=yes to avoid pointless throttling.
339 #mail_log_max_lines_per_sec = 10
341 # Don't use mmap() at all. This is required if you store indexes to shared
342 # filesystems (NFS or clustered filesystem).
345 # Rely on O_EXCL to work when creating dotlock files. NFS supports O_EXCL
346 # since version 3, so this should be safe to use nowadays by default.
347 #dotlock_use_excl = yes
349 # Don't use fsync() or fdatasync() calls. This makes the performance better
350 # at the cost of potential data loss if the server (or the file server)
354 # Mail storage exists in NFS. Set this to yes to make Dovecot flush NFS caches
355 # whenever needed. If you're using only a single mail server this isn't needed.
356 #mail_nfs_storage = no
357 # Mail index files also exist in NFS. Setting this to yes requires
358 # mmap_disable=yes and fsync_disable=no.
361 # Locking method for index files. Alternatives are fcntl, flock and dotlock.
362 # Dotlocking uses some tricks which may create more disk I/O than other locking
363 # methods. NFS users: flock doesn't work, remember to change mmap_disable.
366 # Drop all privileges before exec()ing the mail process. This is mostly
367 # meant for debugging, otherwise you don't get core dumps. It could be a small
368 # security risk if you use single UID for multiple users, as the users could
369 # ptrace() each others processes then.
370 #mail_drop_priv_before_exec = no
372 # Show more verbose process titles (in ps). Currently shows user name and
373 # IP address. Useful for seeing who are actually using the IMAP processes
374 # (eg. shared mailboxes or if same uid is used for multiple accounts).
375 #verbose_proctitle = no
377 # Valid UID range for users, defaults to 500 and above. This is mostly
378 # to make sure that users can't log in as daemons or other system users.
379 # Note that denying root logins is hardcoded to dovecot binary and can't
380 # be done even if first_valid_uid is set to 0.
381 #first_valid_uid = 500
384 # Valid GID range for users, defaults to non-root/wheel. Users having
385 # non-valid GID as primary group ID aren't allowed to log in. If user
386 # belongs to supplementary groups with non-valid GIDs, those groups are
391 # Maximum number of running mail processes. When this limit is reached,
392 # new users aren't allowed to log in.
393 #max_mail_processes = 512
395 # Set max. process size in megabytes. Most of the memory goes to mmap()ing
396 # files, so it shouldn't harm much even if this limit is set pretty high.
397 #mail_process_size = 256
399 # Maximum allowed length for mail keyword name. It's only forced when trying
400 # to create new keywords.
401 #mail_max_keyword_length = 50
403 # ':' separated list of directories under which chrooting is allowed for mail
404 # processes (ie. /var/mail will allow chrooting to /var/mail/foo/bar too).
405 # This setting doesn't affect login_chroot, mail_chroot or auth chroot
406 # settings. If this setting is empty, "/./" in home dirs are ignored.
407 # WARNING: Never add directories here which local users can modify, that
408 # may lead to root exploit. Usually this should be done only if you don't
409 # allow shell access for users. <doc/wiki/Chrooting.txt>
412 # Default chroot directory for mail processes. This can be overridden for
413 # specific users in user database by giving /./ in user's home directory
414 # (eg. /home/./user chroots into /home). Note that usually there is no real
415 # need to do chrooting, Dovecot doesn't allow users to access files outside
416 # their mail directory anyway. If your home directories are prefixed with
417 # the chroot directory, append "/." to mail_chroot. <doc/wiki/Chrooting.txt>
421 ## Mailbox handling optimizations
424 # The minimum number of mails in a mailbox before updates are done to cache
425 # file. This allows optimizing Dovecot's behavior to do less disk writes at
426 # the cost of more disk reads.
427 #mail_cache_min_mail_count = 0
429 # When IDLE command is running, mailbox is checked once in a while to see if
430 # there are any new mails or other changes. This setting defines the minimum
431 # time in seconds to wait between those checks. Dovecot can also use dnotify,
432 # inotify and kqueue to find out immediately when changes occur.
433 #mailbox_idle_check_interval = 30
435 # Save mails with CR+LF instead of plain LF. This makes sending those mails
436 # take less CPU, especially with sendfile() syscall with Linux and FreeBSD.
437 # But it also creates a bit more disk I/O which may just make it slower.
438 # Also note that if other software reads the mboxes/maildirs, they may handle
439 # the extra CRs wrong and cause problems.
443 ## Maildir-specific settings
446 # By default LIST command returns all entries in maildir beginning with a dot.
447 # Enabling this option makes Dovecot return only entries which are directories.
448 # This is done by stat()ing each entry, so it causes more disk I/O.
449 # (For systems setting struct dirent->d_type, this check is free and it's
450 # done always regardless of this setting)
451 #maildir_stat_dirs = no
453 # When copying a message, do it with hard links whenever possible. This makes
454 # the performance much better, and it's unlikely to have any side effects.
455 #maildir_copy_with_hardlinks = yes
457 # When copying a message, try to preserve the base filename. Only if the
458 # destination mailbox already contains the same name (ie. the mail is being
459 # copied there twice), a new name is given. The destination filename check is
460 # done only by looking at dovecot-uidlist file, so if something outside
461 # Dovecot does similar filename preserving copies, you may run into problems.
462 # NOTE: This setting requires maildir_copy_with_hardlinks = yes to work.
463 #maildir_copy_preserve_filename = no
465 # Assume Dovecot is the only MUA accessing Maildir: Scan cur/ directory only
466 # when its mtime changes unexpectedly or when we can't find the mail otherwise.
467 #maildir_very_dirty_syncs = no
470 ## mbox-specific settings
473 # Which locking methods to use for locking mbox. There are four available:
474 # dotlock: Create <mailbox>.lock file. This is the oldest and most NFS-safe
475 # solution. If you want to use /var/mail/ like directory, the users
476 # will need write access to that directory.
477 # dotlock_try: Same as dotlock, but if it fails because of permissions or
478 # because there isn't enough disk space, just skip it.
479 # fcntl : Use this if possible. Works with NFS too if lockd is used.
480 # flock : May not exist in all systems. Doesn't work with NFS.
481 # lockf : May not exist in all systems. Doesn't work with NFS.
483 # You can use multiple locking methods; if you do the order they're declared
484 # in is important to avoid deadlocks if other MTAs/MUAs are using multiple
485 # locking methods as well. Some operating systems don't allow using some of
486 # them simultaneously.
487 #mbox_read_locks = fcntl
488 #mbox_write_locks = dotlock fcntl
490 # Maximum time in seconds to wait for lock (all of them) before aborting.
491 #mbox_lock_timeout = 300
493 # If dotlock exists but the mailbox isn't modified in any way, override the
494 # lock file after this many seconds.
495 #mbox_dotlock_change_timeout = 120
497 # When mbox changes unexpectedly we have to fully read it to find out what
498 # changed. If the mbox is large this can take a long time. Since the change
499 # is usually just a newly appended mail, it'd be faster to simply read the
500 # new mails. If this setting is enabled, Dovecot does this but still safely
501 # fallbacks to re-reading the whole mbox file whenever something in mbox isn't
502 # how it's expected to be. The only real downside to this setting is that if
503 # some other MUA changes message flags, Dovecot doesn't notice it immediately.
504 # Note that a full sync is done with SELECT, EXAMINE, EXPUNGE and CHECK
506 #mbox_dirty_syncs = yes
508 # Like mbox_dirty_syncs, but don't do full syncs even with SELECT, EXAMINE,
509 # EXPUNGE or CHECK commands. If this is set, mbox_dirty_syncs is ignored.
510 #mbox_very_dirty_syncs = no
512 # Delay writing mbox headers until doing a full write sync (EXPUNGE and CHECK
513 # commands and when closing the mailbox). This is especially useful for POP3
514 # where clients often delete all mails. The downside is that our changes
515 # aren't immediately visible to other MUAs.
516 #mbox_lazy_writes = yes
518 # If mbox size is smaller than this (in kilobytes), don't write index files.
519 # If an index file already exists it's still read, just not updated.
520 #mbox_min_index_size = 0
523 ## dbox-specific settings
526 # Maximum dbox file size in kilobytes until it's rotated.
527 #dbox_rotate_size = 2048
529 # Minimum dbox file size in kilobytes before it's rotated
530 # (overrides dbox_rotate_days)
531 #dbox_rotate_min_size = 16
533 # Maximum dbox file age in days until it's rotated. Day always begins from
534 # midnight, so 1 = today, 2 = yesterday, etc. 0 = check disabled.
535 #dbox_rotate_days = 0
538 ## IMAP specific settings
542 # Login executable location.
543 #login_executable = /usr/libexec/dovecot/imap-login
545 # IMAP executable location. Changing this allows you to execute other
546 # binaries before the imap process is executed.
548 # This would write rawlogs into ~/dovecot.rawlog/ directory:
549 # mail_executable = /usr/libexec/dovecot/rawlog /usr/libexec/dovecot/imap
551 # This would attach gdb into the imap process and write backtraces into
552 # /tmp/gdbhelper.* files:
553 # mail_executable = /usr/libexec/dovecot/gdbhelper /usr/libexec/dovecot/imap
555 #mail_executable = /usr/libexec/dovecot/imap
557 # Maximum IMAP command line length in bytes. Some clients generate very long
558 # command lines with huge mailboxes, so you may need to raise this if you get
559 # "Too long argument" or "IMAP command line too large" errors often.
560 #imap_max_line_length = 65536
562 # Maximum number of IMAP connections allowed for a user from each IP address.
563 # NOTE: The username is compared case-sensitively.
564 #mail_max_userip_connections = 10
566 # Support for dynamically loadable plugins. mail_plugins is a space separated
567 # list of plugins to load.
569 #mail_plugin_dir = /usr/lib/dovecot/imap
571 # IMAP logout format string:
572 # %i - total number of bytes read from client
573 # %o - total number of bytes sent to client
574 #imap_logout_format = bytes=%i/%o
576 # Override the IMAP CAPABILITY response.
579 # ID field names and values to send to clients. Using * as the value makes
580 # Dovecot use the default value. The following fields have default values
581 # currently: name, version, os, os-version, support-url, support-email.
584 # ID fields sent by client to log. * means everything.
587 # Workarounds for various client bugs:
589 # Send EXISTS/RECENT new mail notifications only when replying to NOOP
590 # and CHECK commands. Some clients ignore them otherwise, for example OSX
591 # Mail (<v2.1). Outlook Express breaks more badly though, without this it
592 # may show user "Message no longer in server" errors. Note that OE6 still
593 # breaks even with this workaround if synchronization is set to
596 # Netscape 4.x breaks if message headers don't end with the empty "end of
597 # headers" line. Normally all messages have this, but setting this
598 # workaround makes sure that Netscape never breaks by adding the line if
599 # it doesn't exist. This is done only for FETCH BODY[HEADER.FIELDS..]
600 # commands. Note that RFC says this shouldn't be done.
601 # tb-extra-mailbox-sep:
602 # With mbox storage a mailbox can contain either mails or submailboxes,
603 # but not both. Thunderbird separates these two by forcing server to
604 # accept '/' suffix in mailbox names in subscriptions list.
605 # The list is space-separated.
606 #imap_client_workarounds =
610 ## POP3 specific settings
614 # Login executable location.
615 #login_executable = /usr/libexec/dovecot/pop3-login
617 # POP3 executable location. See IMAP's mail_executable above for examples
618 # how this could be changed.
619 #mail_executable = /usr/libexec/dovecot/pop3
621 # Don't try to set mails non-recent or seen with POP3 sessions. This is
622 # mostly intended to reduce disk I/O. With maildir it doesn't move files
623 # from new/ to cur/, with mbox it doesn't write Status-header.
624 #pop3_no_flag_updates = no
626 # Support LAST command which exists in old POP3 specs, but has been removed
627 # from new ones. Some clients still wish to use this though. Enabling this
628 # makes RSET command clear all \Seen flags from messages.
629 #pop3_enable_last = no
631 # If mail has X-UIDL header, use it as the mail's UIDL.
632 #pop3_reuse_xuidl = no
634 # Keep the mailbox locked for the entire POP3 session.
635 #pop3_lock_session = no
637 # POP3 UIDL (unique mail identifier) format to use. You can use following
638 # variables, along with the variable modifiers described in
639 # doc/wiki/Variables.txt (e.g. %Uf for the filename in uppercase)
641 # %v - Mailbox's IMAP UIDVALIDITY
642 # %u - Mail's IMAP UID
643 # %m - MD5 sum of the mailbox headers in hex (mbox only)
644 # %f - filename (maildir only)
646 # If you want UIDL compatibility with other POP3 servers, use:
647 # UW's ipop3d : %08Xv%08Xu
648 # Courier : %f or %v-%u (both might be used simultaneosly)
649 # Cyrus (<= 2.1.3) : %u
650 # Cyrus (>= 2.1.4) : %v.%u
651 # Dovecot v0.99.x : %v.%u
654 # Note that Outlook 2003 seems to have problems with %v.%u format which was
655 # Dovecot's default, so if you're building a new server it would be a good
656 # idea to change this. %08Xu%08Xv should be pretty fail-safe.
658 #pop3_uidl_format = %08Xu%08Xv
660 # POP3 logout format string:
661 # %i - total number of bytes read from client
662 # %o - total number of bytes sent to client
663 # %t - number of TOP commands
664 # %p - number of bytes sent to client as a result of TOP command
665 # %r - number of RETR commands
666 # %b - number of bytes sent to client as a result of RETR command
667 # %d - number of deleted messages
668 # %m - number of messages (before deletion)
669 # %s - mailbox size in bytes (before deletion)
670 #pop3_logout_format = top=%t/%p, retr=%r/%b, del=%d/%m, size=%s
672 # Maximum number of POP3 connections allowed for a user from each IP address.
673 # NOTE: The username is compared case-sensitively.
674 #mail_max_userip_connections = 3
676 # Support for dynamically loadable plugins. mail_plugins is a space separated
677 # list of plugins to load.
679 #mail_plugin_dir = /usr/lib/dovecot/pop3
681 # Workarounds for various client bugs:
683 # Outlook and Outlook Express hang if mails contain NUL characters.
684 # This setting replaces them with 0x80 character.
686 # Outlook Express and Netscape Mail breaks if end of headers-line is
687 # missing. This option simply sends it if it's missing.
688 # The list is space-separated.
689 #pop3_client_workarounds =
693 ## MANAGESIEVE specific settings
696 protocol managesieve {
697 # Login executable location.
698 #login_executable = /usr/libexec/dovecot/managesieve-login
700 # MANAGESIEVE executable location. See IMAP's mail_executable above for
701 # examples how this could be changed.
702 #mail_executable = /usr/libexec/dovecot/managesieve
704 # Maximum MANAGESIEVE command line length in bytes. This setting is
705 # directly borrowed from IMAP. But, since long command lines are very
706 # unlikely with MANAGESIEVE, changing this will not be very useful.
707 #managesieve_max_line_length = 65536
709 # If, for some inobvious reason, the sieve_storage remains unset, the
710 # managesieve daemon uses the specification of the mail_location to find out
711 # where to store the sieve files (see explaination in README.managesieve).
712 # The example below, when uncommented, overrides any global mail_location
713 # specification and stores all the scripts in '~/mail/sieve' if sieve_storage
714 # is unset. However, you should always use the sieve_storage setting.
715 # mail_location = mbox:~/mail
717 # To fool managesieve clients that are focused on timesieved you can
718 # specify the IMPLEMENTATION capability that the dovecot reports to clients
719 # (default: dovecot).
720 #managesieve_implementation_string = Cyrus timsieved v2.2.13
724 ## LDA specific settings
728 # Address to use when sending rejection mails.
729 postmaster_address = postmaster@example.com
731 # Hostname to use in various parts of sent mails, eg. in Message-Id.
732 # Default is the system's real hostname.
735 # Support for dynamically loadable plugins. mail_plugins is a space separated
736 # list of plugins to load.
738 #mail_plugin_dir = /usr/lib/dovecot/lda
740 # If user is over quota, return with temporary failure instead of
742 #quota_full_tempfail = no
744 # Format to use for logging mail deliveries. You can use variables:
745 # %$ - Delivery status message (e.g. "saved to INBOX")
749 #deliver_log_format = msgid=%m: %$
751 # Binary to use for sending mails.
752 #sendmail_path = /usr/lib/sendmail
754 # Subject: header to use for rejection mails. You can use the same variables
755 # as for rejection_reason below.
756 #rejection_subject = Rejected: %s
758 # Human readable error message for rejection mails. You can use variables:
759 # %n = CRLF, %r = reason, %s = original subject, %t = recipient
760 #rejection_reason = Your message to <%t> was automatically rejected:%n%r
762 # UNIX socket path to master authentication server to find users.
763 #auth_socket_path = /var/run/dovecot/auth-master
767 ## Authentication processes
770 # Executable location
771 #auth_executable = /usr/libexec/dovecot/dovecot-auth
773 # Set max. process size in megabytes.
774 #auth_process_size = 256
776 # Authentication cache size in kilobytes. 0 means it's disabled.
777 # Note that bsdauth, PAM and vpopmail require cache_key to be set for caching
780 # Time to live in seconds for cached data. After this many seconds the cached
781 # record is no longer used, *except* if the main database lookup returns
782 # internal failure. We also try to handle password changes automatically: If
783 # user's previous authentication was successful, but this one wasn't, the
784 # cache isn't used. For now this works only with plaintext authentication.
785 #auth_cache_ttl = 3600
786 # TTL for negative hits (user not found). 0 disables caching them completely.
787 #auth_cache_negative_ttl = 3600
789 # Space separated list of realms for SASL authentication mechanisms that need
790 # them. You can leave it empty if you don't want to support multiple realms.
791 # Many clients simply use the first one listed here, so keep the default realm
795 # Default realm/domain to use if none was specified. This is used for both
796 # SASL realms and appending @domain to username in plaintext logins.
797 #auth_default_realm =
799 # List of allowed characters in username. If the user-given username contains
800 # a character not listed in here, the login automatically fails. This is just
801 # an extra check to make sure user can't exploit any potential quote escaping
802 # vulnerabilities with SQL/LDAP databases. If you want to allow all characters,
803 # set this value to empty.
804 #auth_username_chars = abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@
806 # Username character translations before it's looked up from databases. The
807 # value contains series of from -> to characters. For example "#@/@" means
808 # that '#' and '/' characters are translated to '@'.
809 #auth_username_translation =
811 # Username formatting before it's looked up from databases. You can use
812 # the standard variables here, eg. %Lu would lowercase the username, %n would
813 # drop away the domain if it was given, or "%n-AT-%d" would change the '@' into
814 # "-AT-". This translation is done after auth_username_translation changes.
815 #auth_username_format =
817 # If you want to allow master users to log in by specifying the master
818 # username within the normal username string (ie. not using SASL mechanism's
819 # support for it), you can specify the separator character here. The format
820 # is then <username><separator><master username>. UW-IMAP uses "*" as the
821 # separator, so that could be a good choice.
822 #auth_master_user_separator =
824 # Username to use for users logging in with ANONYMOUS SASL mechanism
825 #auth_anonymous_username = anonymous
827 # More verbose logging. Useful for figuring out why authentication isn't
831 # Even more verbose logging for debugging purposes. Shows for example SQL
835 # In case of password mismatches, log the passwords and used scheme so the
836 # problem can be debugged. Enabling this also enables auth_debug.
837 #auth_debug_passwords = no
839 # Maximum number of dovecot-auth worker processes. They're used to execute
840 # blocking passdb and userdb queries (eg. MySQL and PAM). They're
841 # automatically created and destroyed as needed.
842 #auth_worker_max_count = 30
844 # Host name to use in GSSAPI principal names. The default is to use the
845 # name returned by gethostname(). Use "$ALL" to allow all keytab entries.
846 #auth_gssapi_hostname =
848 # Kerberos keytab to use for the GSSAPI mechanism. Will use the system
849 # default (usually /etc/krb5.keytab) if not specified.
852 # Do NTLM and GSS-SPNEGO authentication using Samba's winbind daemon and
853 # ntlm_auth helper. <doc/wiki/Authentication/Mechanisms/Winbind.txt>
854 #auth_use_winbind = no
856 # Path for Samba's ntlm_auth helper binary.
857 #auth_winbind_helper_path = /usr/bin/ntlm_auth
859 # Number of seconds to delay before replying to failed authentications.
860 #auth_failure_delay = 2
863 # Space separated list of wanted authentication mechanisms:
864 # plain login digest-md5 cram-md5 ntlm rpa apop anonymous gssapi otp skey
866 # NOTE: See also disable_plaintext_auth setting.
870 # Password database is used to verify user's password (and nothing more).
871 # You can have multiple passdbs and userdbs. This is useful if you want to
872 # allow both system users (/etc/passwd) and virtual users to login without
873 # duplicating the system users into virtual database.
875 # <doc/wiki/PasswordDatabase.txt>
877 # By adding master=yes setting inside a passdb you make the passdb a list
878 # of "master users", who can log in as anyone else. Unless you're using PAM,
879 # you probably still want the destination user to be looked up from passdb
880 # that it really exists. This can be done by adding pass=yes setting to the
881 # master passdb. <doc/wiki/Authentication.MasterUsers.txt>
883 # Users can be temporarily disabled by adding a passdb with deny=yes.
884 # If the user is found from that database, authentication will fail.
885 # The deny passdb should always be specified before others, so it gets
886 # checked first. Here's an example:
888 #passdb passwd-file {
889 # File contains a list of usernames, one per line
890 #args = /etc/dovecot.deny
894 # PAM authentication. Preferred nowadays by most systems.
895 # Note that PAM can only be used to verify if user's password is correct,
896 # so it can't be used as userdb. If you don't want to use a separate user
897 # database (passwd usually), you can use static userdb.
898 # REMEMBER: You'll need /etc/pam.d/dovecot file created for PAM
899 # authentication to actually work. <doc/wiki/PasswordDatabase.PAM.txt>
901 # [session=yes] [setcred=yes] [failure_show_msg=yes] [max_requests=<n>]
902 # [cache_key=<key>] [<service name>]
904 # session=yes makes Dovecot open and immediately close PAM session. Some
905 # PAM plugins need this to work, such as pam_mkhomedir.
907 # setcred=yes makes Dovecot establish PAM credentials if some PAM plugins
908 # need that. They aren't ever deleted though, so this isn't enabled by
911 # max_requests specifies how many PAM lookups to do in one process before
912 # recreating the process. The default is 100, because many PAM plugins
915 # cache_key can be used to enable authentication caching for PAM
916 # (auth_cache_size also needs to be set). It isn't enabled by default
917 # because PAM modules can do all kinds of checks besides checking password,
918 # such as checking IP address. Dovecot can't know about these checks
919 # without some help. cache_key is simply a list of variables (see
920 # doc/wiki/Variables.txt) which must match for the cached data to be used.
921 # Here are some examples:
922 # %u - Username must match. Probably sufficient for most uses.
923 # %u%r - Username and remote IP address must match.
924 # %u%s - Username and service (ie. IMAP, POP3) must match.
926 # The service name can contain variables, for example %Ls expands to
930 # args = session=yes %Ls
931 # args = cache_key=%u dovecot
935 # System users (NSS, /etc/passwd, or similiar)
936 # In many systems nowadays this uses Name Service Switch, which is
937 # configured in /etc/nsswitch.conf. <doc/wiki/AuthDatabase.Passwd.txt>
939 # [blocking=yes] - See userdb passwd for explanation
943 # Shadow passwords for system users (NSS, /etc/shadow or similiar).
944 # Deprecated by PAM nowadays.
945 # <doc/wiki/PasswordDatabase.Shadow.txt>
947 # [blocking=yes] - See userdb passwd for explanation
951 # PAM-like authentication for OpenBSD.
952 # <doc/wiki/PasswordDatabase.BSDAuth.txt>
954 # [cache_key=<key>] - See cache_key in PAM for explanation.
958 # passwd-like file with specified location
959 # <doc/wiki/AuthDatabase.PasswdFile.txt>
960 #passdb passwd-file {
961 # [scheme=<default password scheme>] [username_format=<format>]
962 # <Path for passwd-file>
966 # checkpassword executable authentication
967 # NOTE: You will probably want to use "userdb prefetch" with this.
968 # <doc/wiki/AuthDatabase.CheckPassword.txt>
969 #passdb checkpassword {
970 # Path for checkpassword binary
974 # SQL database <doc/wiki/AuthDatabase.SQL.txt>
976 # Path for SQL configuration file, see doc/dovecot-sql-example.conf
980 # LDAP database <doc/wiki/AuthDatabase.LDAP.txt>
982 # Path for LDAP configuration file, see doc/dovecot-ldap-example.conf
986 # vpopmail authentication <doc/wiki/AuthDatabase.VPopMail.txt>
988 # [cache_key=<key>] - See cache_key in PAM for explanation.
989 # [quota_template=<template>] - %q expands to Maildir++ quota
990 # (eg. quota_template=quota_rule=*:backend=%q)
995 # User database specifies where mails are located and what user/group IDs
996 # own them. For single-UID configuration use "static".
998 # <doc/wiki/UserDatabase.txt>
1001 # "prefetch" user database means that the passdb already provided the
1002 # needed information and there's no need to do a separate userdb lookup.
1003 # This can be made to work with SQL and LDAP databases, see their example
1004 # configuration files for more information how to do it.
1005 # <doc/wiki/UserDatabase.Prefetch.txt>
1009 # System users (NSS, /etc/passwd, or similiar). In many systems nowadays this
1010 # uses Name Service Switch, which is configured in /etc/nsswitch.conf.
1011 # <doc/wiki/AuthDatabase.Passwd.txt>
1013 # [blocking=yes] - By default the lookups are done in the main dovecot-auth
1014 # process. This setting causes the lookups to be done in auth worker
1015 # proceses. Useful with remote NSS lookups that may block.
1016 # NOTE: Be sure to use this setting with nss_ldap or users might get
1017 # logged in as each others!
1021 # passwd-like file with specified location
1022 # <doc/wiki/AuthDatabase.PasswdFile.txt>
1023 #userdb passwd-file {
1024 # [username_format=<format>] <Path for passwd-file>
1028 # checkpassword executable user database lookup
1029 # <doc/wiki/AuthDatabase.CheckPassword.txt>
1030 #userdb checkpassword {
1031 # Path for checkpassword binary
1035 # static settings generated from template <doc/wiki/UserDatabase.Static.txt>
1037 # Template for the fields. Can return anything a userdb could normally
1038 # return. For example:
1040 # args = uid=500 gid=500 home=/var/mail/%u
1042 # If you use deliver, it needs to look up users only from the userdb. This
1043 # of course doesn't work with static because there is no list of users.
1044 # Normally static userdb handles this by doing a passdb lookup. This works
1045 # with most passdbs, with PAM being the most notable exception. If you do
1046 # the user verification another way, you can add allow_all_users=yes to
1047 # the args in which case the passdb lookup is skipped.
1052 # SQL database <doc/wiki/AuthDatabase.SQL.txt>
1054 # Path for SQL configuration file, see doc/dovecot-sql-example.conf
1058 # LDAP database <doc/wiki/AuthDatabase.LDAP.txt>
1060 # Path for LDAP configuration file, see doc/dovecot-ldap-example.conf
1064 # vpopmail <doc/wiki/AuthDatabase.VPopMail.txt>
1068 # User to use for the process. This user needs access to only user and
1069 # password databases, nothing else. Only shadow and pam authentication
1070 # requires roots, so use something else if possible. Note that passwd
1071 # authentication with BSDs internally accesses shadow files, which also
1072 # requires roots. Note that this user is NOT used to access mails.
1073 # That user is specified by userdb above.
1076 # Directory where to chroot the process. Most authentication backends don't
1077 # work if this is set, and there's no point chrooting if auth_user is root.
1078 # Note that valid_chroot_dirs isn't needed to use this setting.
1081 # Number of authentication processes to create
1084 # Require a valid SSL client certificate or the authentication fails.
1085 #ssl_require_client_cert = no
1087 # Take the username from client's SSL certificate, using
1088 # X509_NAME_get_text_by_NID() which returns the subject's DN's
1090 #ssl_username_from_cert = no
1092 # It's possible to export the authentication interface to other programs:
1095 # Master socket provides access to userdb information. It's typically
1096 # used to give Dovecot's local delivery agent access to userdb so it
1097 # can find mailbox locations.
1098 #path = /var/run/dovecot/auth-master
1100 # Default user/group is the one who started dovecot-auth (root)
1105 # The client socket is generally safe to export to everyone. Typical use
1106 # is to export it to your SMTP server so it can do SMTP AUTH lookups
1108 #path = /var/run/dovecot/auth-client
1114 # If you wish to use another authentication server than dovecot-auth, you can
1115 # use connect sockets. They are assumed to be already running, Dovecot's master
1116 # process only tries to connect to them. They don't need any other settings
1117 # than the path for the master socket, as the configuration is done elsewhere.
1118 # Note that the client sockets must exist in the login_dir.
1122 # path = /var/run/dovecot/auth-master
1128 ## Dictionary server settings
1131 # Dictionary can be used by some plugins to store key=value lists.
1132 # Currently this is only used by dict quota backend. The dictionary can be
1133 # used either directly or though a dictionary server. The following dict block
1134 # maps dictionary names to URIs when the server is used. These can then be
1135 # referenced using URIs in format "proxy::<name>".
1138 #quota = mysql:/etc/dovecot-dict-quota.conf
1139 #expire = db:/var/lib/dovecot/expire.db
1142 # Path to Berkeley DB's configuration file. See doc/dovecot-db-example.conf
1150 # Here you can give some extra environment variables to mail processes.
1151 # This is mostly meant for passing parameters to plugins. %variable
1152 # expansion is done for all values.
1154 # Quota plugin. Multiple backends are supported:
1155 # dirsize: Find and sum all the files found from mail directory.
1156 # Extremely SLOW with Maildir. It'll eat your CPU and disk I/O.
1157 # dict: Keep quota stored in dictionary (eg. SQL)
1158 # maildir: Maildir++ quota
1159 # fs: Read-only support for filesystem quota
1161 # Quota limits are set using "quota_rule" parameters, either in here or in
1162 # userdb. It's also possible to give mailbox-specific limits, for example:
1163 # quota_rule = *:storage=1048576
1164 # quota_rule2 = Trash:storage=102400
1165 # User has now 1GB quota, but when saving to Trash mailbox the user gets
1168 # Multiple quota roots are also possible, for example:
1169 # quota = dict:user::proxy::quota
1170 # quota2 = dict:domain:%d:proxy::quota_domain
1171 # quota_rule = *:storage=102400
1172 # quota2_rule = *:storage=1048576
1173 # Gives each user their own 100MB quota and one shared 1GB quota within
1176 # You can execute a given command when user exceeds a specified quota limit.
1177 # Each quota root has separate limits. Only the command for the first
1178 # exceeded limit is excecuted, so put the highest limit first.
1179 # Note that % needs to be escaped as %%, otherwise "% " expands to empty.
1180 # quota_warning = storage=95%% /usr/local/bin/quota-warning.sh 95
1181 # quota_warning2 = storage=80%% /usr/local/bin/quota-warning.sh 80
1184 # ACL plugin. vfile backend reads ACLs from "dovecot-acl" file from maildir
1185 # directory. You can also optionally give a global ACL directory path where
1186 # ACLs are applied to all users' mailboxes. The global ACL directory contains
1187 # one file for each mailbox, eg. INBOX or sub.mailbox. cache_secs parameter
1188 # specifies how many seconds to wait between stat()ing dovecot-acl file
1189 # to see if it changed.
1190 #acl = vfile:/etc/dovecot-acls:cache_secs=300
1192 # To let users LIST mailboxes shared by other users, Dovecot needs a
1193 # shared mailbox dictionary. For example:
1194 #acl_shared_dict = file:/var/lib/dovecot/shared-mailboxes
1196 # Convert plugin. If set, specifies the source storage path which is
1197 # converted to destination storage (mail_location) when the user logs in.
1198 # The existing mail directory is renamed to <dir>-converted.
1199 #convert_mail = mbox:%h/mail
1200 # Skip mailboxes which we can't open successfully instead of aborting.
1201 #convert_skip_broken_mailboxes = no
1202 # Skip directories beginning with '.'
1203 #convert_skip_dotdirs = no
1204 # If source storage has mailbox names with destination storage's hierarchy
1205 # separators, replace them with this character.
1206 #convert_alt_hierarchy_char = _
1208 # Trash plugin. When saving a message would make user go over quota, this
1209 # plugin automatically deletes the oldest mails from configured mailboxes
1210 # until the message can be saved within quota limits. The configuration file
1211 # is a text file where each line is in format: <priority> <mailbox name>
1212 # Mails are first deleted in lowest -> highest priority number order
1213 #trash = /etc/dovecot-trash.conf
1215 # Expire plugin. Mails are expunged from mailboxes after being there the
1216 # configurable time. The first expiration date for each mailbox is stored in
1217 # a dictionary so it can be quickly determined which mailboxes contain
1218 # expired mails. The actual expunging is done in a nightly cronjob, which
1220 # dovecot --exec-mail ext /usr/libexec/dovecot/expire-tool
1221 #expire = Trash 7 Spam 30
1222 #expire_dict = proxy::expire
1224 # Lazy expunge plugin. Currently works only with maildirs. When a user
1225 # expunges mails, the mails are moved to a mailbox in another namespace
1226 # (1st). When a mailbox is deleted, the mailbox is moved to another namespace
1227 # (2nd) as well. Also if the deleted mailbox had any expunged messages,
1228 # they're moved to a 3rd namespace. The mails won't be counted in quota,
1229 # and they're not deleted automatically (use a cronjob or something).
1230 #lazy_expunge = .EXPUNGED/ .DELETED/ .DELETED/.EXPUNGED/
1232 # Events to log. Also available: flag_change append
1233 #mail_log_events = delete undelete expunge copy mailbox_delete mailbox_rename
1234 # Group events within a transaction to one line.
1235 #mail_log_group_events =
1236 # Available fields: uid, box, msgid, from, subject, size, vsize, flags
1237 # size and vsize are available only for expunge and copy events.
1238 #mail_log_fields = uid box msgid size
1240 # Sieve plugin (http://wiki.dovecot.org/LDA/Sieve) and ManageSieve service
1242 # Location of the active script. When ManageSieve is used this is actually
1243 # a symlink pointing to the active script in the sieve storage directory.
1244 #sieve=~/.dovecot.sieve
1246 # The path to the directory where the personal Sieve scripts are stored. For
1247 # ManageSieve this is where the uploaded scripts are stored.