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## Dovecot configuration file



# If you're in a hurry, see http://wiki.dovecot.org/QuickConfiguration



# "dovecot -n" command gives a clean output of the changed settings. Use it

# instead of copy&pasting this file when posting to the Dovecot mailing list.



# '#' character and everything after it is treated as comments. Extra spaces

# and tabs are ignored. If you want to use either of these explicitly, put the

# value inside quotes, eg.: key = "# char and trailing whitespace  "



# Default values are shown for each setting, it's not required to uncomment

# any of the lines. Exception to this are paths, they're just examples with

# the real defaults being based on configure options. The paths listed here

# are for configure --prefix=/usr --sysconfdir=/etc --localstatedir=/var

# --with-ssldir=/etc/ssl



# Base directory where to store runtime data.

base_dir = /var/run/dovecot/



# Protocols we want to be serving: imap imaps pop3 pop3s

# If you only want to use dovecot-auth, you can set this to "none".

#protocols = imap imaps

protocols = pop3



# IP or host address where to listen in for connections. It's not currently

# possible to specify multiple addresses. "*" listens in all IPv4 interfaces.

# "[::]" listens in all IPv6 interfaces, but may also listen in all IPv4

# interfaces depending on the operating system.

#

# If you want to specify ports for each service, you will need to configure

# these settings inside the protocol imap/pop3 { ... } section, so you can

# specify different ports for IMAP/POP3. For example:

#  protocol imap {

#    listen = *:10143

#    ssl_listen = *:10943

#    ..

#  }

#  protocol pop3 {

#    listen = *:10100

#    ..

#  }

listen = *



# Disable LOGIN command and all other plaintext authentications unless

# SSL/TLS is used (LOGINDISABLED capability). Note that if the remote IP

# matches the local IP (ie. you're connecting from the same computer), the

# connection is considered secure and plaintext authentication is allowed.

disable_plaintext_auth = no



# Should all IMAP and POP3 processes be killed when Dovecot master process

# shuts down. Setting this to "no" means that Dovecot can be upgraded without

# forcing existing client connections to close (although that could also be

# a problem if the upgrade is eg. because of a security fix). This however

# means that after master process has died, the client processes can't write

# to log files anymore.

#shutdown_clients = yes



##

## Logging

##



# Log file to use for error messages, instead of sending them to syslog.

# /dev/stderr can be used to log into stderr.

#log_path =



# Log file to use for informational and debug messages.

# Default is the same as log_path.

#info_log_path =



# Prefix for each line written to log file. % codes are in strftime(3)

# format.

#log_timestamp = "%b %d %H:%M:%S "

log_timestamp = "%Y-%m-%d %H:%M:%S "



# Syslog facility to use if you're logging to syslog. Usually if you don't

# want to use "mail", you'll use local0..local7. Also other standard

# facilities are supported.

#syslog_facility = mail



##

## SSL settings

##



# IP or host address where to listen in for SSL connections. Defaults

# to above if not specified.

#ssl_listen =



# Disable SSL/TLS support.

#ssl_disable = no



# PEM encoded X.509 SSL/TLS certificate and private key. They're opened before

# dropping root privileges, so keep the key file unreadable by anyone but

# root.

#ssl_cert_file = /etc/ssl/certs/ssl-cert-snakeoil.pem

#ssl_key_file = /etc/ssl/private/ssl-cert-snakeoil.key



# If key file is password protected, give the password here. Alternatively

# give it when starting dovecot with -p parameter.

#ssl_key_password =

# Request client to send a certificate. If you also want to require it, set

# ssl_require_client_cert=yes in auth section.

#ssl_verify_client_cert = no



# How often to regenerate the SSL parameters file. Generation is quite CPU

# intensive operation. The value is in hours, 0 disables regeneration

# entirely.

#ssl_parameters_regenerate = 168



# SSL ciphers to use

#ssl_cipher_list = ALL:!LOW



# Show protocol level SSL errors.

#verbose_ssl = no



##

## Login processes

##



# <doc/wiki/LoginProcess.txt>



# Directory where authentication process places authentication UNIX sockets

# which login needs to be able to connect to. The sockets are created when

# running as root, so you don't have to worry about permissions. Note that

# everything in this directory is deleted when Dovecot is started.

#login_dir = /var/run/dovecot/login



# chroot login process to the login_dir. Only reason not to do this is if you

# wish to run the whole Dovecot without roots. <doc/wiki/Rootless.txt>

#login_chroot = yes



# User to use for the login process. Create a completely new user for this,

# and don't use it anywhere else. The user must also belong to a group where

# only it has access, it's used to control access for authentication process.

# Note that this user is NOT used to access mails. <doc/wiki/UserIds.txt>

#login_user = dovecot



# Set max. process size in megabytes. If you don't use

# login_process_per_connection you might need to grow this.

#login_process_size = 64



# Should each login be processed in it's own process (yes), or should one

# login process be allowed to process multiple connections (no)? Yes is more

# secure, espcially with SSL/TLS enabled. No is faster since there's no need

# to create processes all the time.

#login_process_per_connection = yes



# Number of login processes to keep for listening new connections.

#login_processes_count = 3



# Maximum number of login processes to create. The listening process count

# usually stays at login_processes_count, but when multiple users start logging

# in at the same time more extra processes are created. To prevent fork-bombing

# we check only once in a second if new processes should be created - if all

# of them are used at the time, we double their amount until the limit set by

# this setting is reached.

#login_max_processes_count = 128



# Maximum number of connections allowed per each login process. This setting

# is used only if login_process_per_connection=no. Once the limit is reached,

# the process notifies master so that it can create a new login process.

# You should make sure that the process has at least

# 16 + login_max_connections * 2 available file descriptors.

#login_max_connections = 256



# Greeting message for clients.

#login_greeting = Dovecot ready.



# Space-separated list of elements we want to log. The elements which have

# a non-empty variable value are joined together to form a comma-separated

# string.

#login_log_format_elements = user=<%u> method=%m rip=%r lip=%l %c



# Login log format. %$ contains login_log_format_elements string, %s contains

# the data we want to log.

#login_log_format = %$: %s



##

## Mailbox locations and namespaces

##



# Location for users' mailboxes. This is the same as the old default_mail_env

# setting. The default is empty, which means that Dovecot tries to find the

# mailboxes automatically. This won't work if the user doesn't have any mail

# yet, so you should explicitly tell Dovecot the full location.

#

# If you're using mbox, giving a path to the INBOX file (eg. /var/mail/%u)

# isn't enough. You'll also need to tell Dovecot where the other mailboxes are

# kept. This is called the "root mail directory", and it must be the first

# path given in the mail_location setting.

#

# There are a few special variables you can use, eg.:

#

#  %u - username

#  %n - user part in user@domain, same as %u if there's no domain

#  %d - domain part in user@domain, empty if there's no domain

#  %h - home directory

#

# See /usr/share/doc/dovecot-common/wiki/Variables.txt for full list. Some

# examples:

#

  mail_location = maildir:/home/%u/mail/

  # mail_location = mbox:~/mail:INBOX=/var/mail/%u

 # mail_location = mbox:/var/mail/%d/%1n/%n:INDEX=/var/indexes/%d/%1n/%n

  # pop3_uidl_format = %08Xu%08Xv

# <doc/wiki/MailLocation.txt>

#

#mail_location =



# If you need to set multiple mailbox locations or want to change default

# namespace settings, you can do it by defining namespace sections.

# NOTE: Namespaces currently work ONLY with IMAP! POP3 and LDA currently ignore

# namespaces completely, they use only the mail_location setting.

#

# You can have private, shared and public namespaces. The only difference

# between them is how Dovecot announces them to client via NAMESPACE

# extension. Shared namespaces are meant for user-owned mailboxes which are

# shared to other users, while public namespaces are for more globally

# accessible mailboxes.

#

# REMEMBER: If you add any namespaces, the default namespace must be added

# explicitly, ie. mail_location does nothing unless you have a namespace

# without a location setting. Default namespace is simply done by having a

# namespace with empty prefix.

#namespace private {

  # Hierarchy separator to use. You should use the same separator for all

  # namespaces or some clients get confused. '/' is usually a good one.

  # The default however depends on the underlying mail storage format.

  #separator =



  # Prefix required to access this namespace. This needs to be different for

  # all namespaces. For example "Public/".

  #prefix =



  # Physical location of the mailbox. This is in same format as

  # mail_location, which is also the default for it.

  #location =



  # There can be only one INBOX, and this setting defines which namespace

  # has it.

  #inbox = yes



  # If namespace is hidden, it's not advertised to clients via NAMESPACE

  # extension or shown in LIST replies. This is mostly useful when converting

  # from another server with different namespaces which you want to depricate

  # but still keep working. For example you can create hidden namespaces with

  # prefixes "~/mail/", "~%u/mail/" and "mail/".

  #hidden = yes

#}



# Group to enable temporarily for privileged operations. Currently this is

# used only for creating mbox dotlock files when creation fails for INBOX.

# Typically this is set to "mail" to give access to /var/mail.

#mail_privileged_group =

mail_privileged_group = mail

# Grant access to these supplementary groups for mail processes. Typically

# these are used to set up access to shared mailboxes. Note that it may be

# dangerous to set these if users can create symlinks (e.g. if "mail" group is

# set here, ln -s /var/mail ~/mail/var could allow a user to delete others'

# mailboxes, or ln -s /secret/shared/box ~/mail/mybox would allow reading it).

#mail_access_groups =



# Allow full filesystem access to clients. There's no access checks other than

# what the operating system does for the active UID/GID. It works with both

# maildir and mboxes, allowing you to prefix mailboxes names with eg. /path/

# or ~user/.

#mail_full_filesystem_access = no



##

## Mail processes

##



# Enable mail process debugging. This can help you figure out why Dovecot

# isn't finding your mails.

#mail_debug = no



# Log prefix for mail processes.

# See /usr/share/doc/dovecot-common/wiki/Variables.txt for list of possible

# variables you can use.

#mail_log_prefix = "%Us(%u): "



# Max. number of lines a mail process is allowed to log per second before it's

# throttled. 0 means unlimited. Typically there's no need to change this

# unless you're using mail_log plugin, which may log a lot.

#mail_log_max_lines_per_sec = 10



# Don't use mmap() at all. This is required if you store indexes to shared

# filesystems (NFS or clustered filesystem).

#mmap_disable = no



# Don't write() to mmaped files. This is required for some operating systems

# which use separate caches for them, such as OpenBSD.

#mmap_no_write = no



# Rely on O_EXCL to work when creating dotlock files. The default is to use

# hard linking. O_EXCL makes the dotlocking faster, but it doesn't always

# work with NFS.

#dotlock_use_excl = no



# Don't use fsync() or fdatasync() calls. This makes the performance better

# at the cost of potential data loss if the server (or the file server)

# goes down.

#fsync_disable = no



# Locking method for index files. Alternatives are fcntl, flock and dotlock.

# Dotlocking uses some tricks which may create more disk I/O than other locking

# methods. NFS users: flock doesn't work, remember to change mmap_disable.

#lock_method = fcntl



# Drop all privileges before exec()ing the mail process. This is mostly

# meant for debugging, otherwise you don't get core dumps. It could be a small

# security risk if you use single UID for multiple users, as the users could

# ptrace() each others processes then.

#mail_drop_priv_before_exec = no



# Show more verbose process titles (in ps). Currently shows user name and

# IP address. Useful for seeing who are actually using the IMAP processes

# (eg. shared mailboxes or if same uid is used for multiple accounts).

#verbose_proctitle = no



# Valid UID range for users, defaults to 500 and above. This is mostly

# to make sure that users can't log in as daemons or other system users.

# Note that denying root logins is hardcoded to dovecot binary and can't

# be done even if first_valid_uid is set to 0.

#first_valid_uid = 500

#last_valid_uid = 0



# Valid GID range for users, defaults to non-root/wheel. Users having

# non-valid GID as primary group ID aren't allowed to log in. If user

# belongs to supplementary groups with non-valid GIDs, those groups are

# not set.

#first_valid_gid = 1

#last_valid_gid = 0



# Maximum number of running mail processes. When this limit is reached,

# new users aren't allowed to log in.

#max_mail_processes = 1024



# Set max. process size in megabytes. Most of the memory goes to mmap()ing

# files, so it shouldn't harm much even if this limit is set pretty high.

#mail_process_size = 256



# Maximum allowed length for mail keyword name. It's only forced when trying

# to create new keywords.

#mail_max_keyword_length = 50



# ':' separated list of directories under which chrooting is allowed for mail

# processes (ie. /var/mail will allow chrooting to /var/mail/foo/bar too).

# This setting doesn't affect login_chroot or auth chroot variables.

# WARNING: Never add directories here which local users can modify, that

# may lead to root exploit. Usually this should be done only if you don't

# allow shell access for users. <doc/wiki/Chrooting.txt>

#valid_chroot_dirs =



# Default chroot directory for mail processes. This can be overridden for

# specific users in user database by giving /./ in user's home directory

# (eg. /home/./user chroots into /home). Note that usually there is no real

# need to do chrooting, Dovecot doesn't allow users to access files outside

# their mail directory anyway. <doc/wiki/Chrooting.txt>

#mail_chroot =



##

## Mailbox handling optimizations

##



# Space-separated list of fields to initially save into cache file. Currently

# these fields are allowed:

#

#  flags, date.sent, date.received, size.virtual, size.physical

#  mime.parts, imap.body, imap.bodystructure

#

# Different IMAP clients work in different ways, so they benefit from

# different cached fields. Some do not benefit from them at all. Caching more

# than necessary generates useless disk I/O, so you don't want to do that

# either.

#

# Dovecot attempts to automatically figure out what client wants and it keeps

# only that. However the first few times a mailbox is opened, Dovecot hasn't

# yet figured out what client needs, so it may not perform optimally. If you

# know what fields the majority of your clients need, it may be useful to set

# these fields by hand. If client doesn't actually use them, Dovecot will

# eventually drop them.

#

# Usually you should just leave this field alone. The potential benefits are

# typically unnoticeable.

#mail_cache_fields =



# Space-separated list of fields that Dovecot should never save to cache file.

# Useful if you want to save disk space at the cost of more I/O when the fields

# needed.

#mail_never_cache_fields =



# The minimum number of mails in a mailbox before updates are done to cache

# file. This allows optimizing Dovecot's behavior to do less disk writes at

# the cost of more disk reads.

#mail_cache_min_mail_count = 0



# When IDLE command is running, mailbox is checked once in a while to see if

# there are any new mails or other changes. This setting defines the minimum

# time in seconds to wait between those checks. Dovecot can also use dnotify,

# inotify and kqueue to find out immediately when changes occur.

#mailbox_idle_check_interval = 30



# Save mails with CR+LF instead of plain LF. This makes sending those mails

# take less CPU, especially with sendfile() syscall with Linux and FreeBSD.

# But it also creates a bit more disk I/O which may just make it slower.

# Also note that if other software reads the mboxes/maildirs, they may handle

# the extra CRs wrong and cause problems.

#mail_save_crlf = no



##

## Maildir-specific settings

##



# By default LIST command returns all entries in maildir beginning with a dot.

# Enabling this option makes Dovecot return only entries which are directories.

# This is done by stat()ing each entry, so it causes more disk I/O.

# (For systems setting struct dirent->d_type, this check is free and it's

# done always regardless of this setting)

#maildir_stat_dirs = no