## Dovecot 1.0 configuration file

# Default values are shown after each value, it's not required to uncomment
# any of the lines. Exception to this are paths, they're just examples
# with 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/

# Port to listen in for IMAP connections. This port is used for TLS
# connections as well. Setting it to 0 disables it.
#imap_port = 143

# Port to listen in for SSL IMAP connections. Setting it to 0 disables it.
#imaps_port = 993

# IP or host address where to listen in for IMAP connections. It's not
# 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.
#imap_listen = *

# IP or host address where to listen in for SSL IMAP connections. Defaults
# to imap_listen if not specified.
#imaps_listen = 

# Disable SSL 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. Included doc/mkcert.sh can be used to easily generate self-signed
# certificate, just make sure to update the domains in dovecot-openssl.cnf
#ssl_cert_file = /etc/ssl/certs/imapd.pem
#ssl_key_file = /etc/ssl/private/imapd.pem

# SSL parameter file. Master process generates this file for login processes.
# It contains Diffie Hellman and RSA parameters.
#ssl_parameters_file = /var/run/dovecot/ssl-parameters.dat

# 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 = 24

# Disable LOGIN command and all other plaintext authentications unless
# SSL/TLS is used (LOGINDISABLED capability)
#disable_plaintext_auth = no

# Use this logfile instead of syslog()
#log_path = 

# For informational messages, use this logfile instead of the default
#info_log_path = 

# Prefix for each line written to log file. % codes are in strftime(3)
# format. Note the extra space at the end of line.
#log_timestamp = %b %d %H:%M:%S 

##
## Login process
##

# Executable location.
#login_executable = /usr/libexec/dovecot/imap-login

# User to use for imap-login process. The user must belong to a group
# where only it has access, it's used to control access for authentication
# process named sockets.
#login_user = imapd

# Set max. process size in megabytes. If you don't use
# login_process_per_connection you might need to grow this.
#login_process_size = 16

# Directory where imap-auth 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 need to give imap-auth any access for it.
#login_dir = /var/run/dovecot/login

# chroot imap-login process to the login_dir. Only reason not to do this
# is if you wish to run the whole imapd without roots.
#login_chroot = yes

# 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 imap-login processes to create. If login_process_per_user is
# yes, this is the number of extra processes waiting for users to log in.
#login_processes_count = 3

# Maximum number of extra login processes to create. The extra 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 limit set by this
# setting is reached. This setting is used only if login_process_per_use is yes.
#login_max_processes_count = 128

# Maximum number of connections allowed in login state. When this limit is
# reached, the oldest connections are dropped. If login_process_per_user
# is no, this is a per-process value, so the absolute maximum number of users
# logging in actually login_processes_count * max_logging_users.
#max_logging_users = 256

##
## IMAP process
##

# Executable location
#imap_executable = /usr/libexec/dovecot/imap

# 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.
#imap_process_size = 256

# Maximum number of running imap processes. When this limit is reached,
# new users aren't allowed to log in.
#max_imap_processes = 1024

# 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/GID ranges for imap users, defaults to 500 and above.
# Note that denying root logins is hardcoded to imap-master binary and
# can't be done even if first_valid_uid is set to 0.
#first_valid_uid = 500
#last_valid_uid = 0

#first_valid_gid = 1
#last_valid_gid = 0

# ':' separated list of directories under which chrooting is allowed for imap
# 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. See doc/configuration.txt for more information.
#valid_chroot_dirs = 

# Default MAIL environment to use when it's not set. By leaving this empty
# dovecot tries to do some automatic detection as described in
# doc/mail-storages.txt. There's a few special variables you can use:
#
#   %u - username
#   %n - user part in user@domain, same as %u if there's no domain
#   %d - domain part in user@domain, empty if user there's no domain
#   %h - home directory
#
# You can also limit a width of string by giving the number of max. characters
# after the '%' character. For example %1u gives the first character of
# username. Some examples:
#
#   maildir:/var/mail/%1u/%u/Maildir
#   mbox:~/mail/:INBOX=/var/mail/%u
#   mbox:/var/mail/%d/%n/:INDEX=/var/indexes/%d/%n
#
#default_mail_env = 

# Space-separated list of fields to cache for all mails. Currently these
# fields are allowed followed by a list of commands they speed up:
#
#  Envelope      - FETCH ENVELOPE and SEARCH FROM, TO, CC, BCC, SUBJECT,
#                  SENTBEFORE, SENTON, SENTSINCE, HEADER MESSAGE-ID,
#                  HEADER IN-REPLY-TO
#  Body          - FETCH BODY
#  Bodystructure - FETCH BODY, BODYSTRUCTURE
#  MessagePart   - FETCH BODY[1.2.3] (ie. body parts), RFC822.SIZE,
#                  SEARCH SMALLER, LARGER, also speeds up BODY/BODYSTRUCTURE
#                  generation. This is always set with mbox mailboxes, and
#                  also default with Maildir.
#
# Different IMAP clients work in different ways, that's why Dovecot by default
# only caches MessagePart which speeds up most operations. Whenever client
# does something where caching could be used, the field is automatically marked
# to be cached later. For example after FETCH BODY the BODY will be cached
# for all new messages. Normally you should leave this alone, unless you know
# what most of your IMAP clients are. Caching more fields than needed makes
# the index files larger and generate useless I/O.
#
# With maildir there's one extra optimization - if nothing is cached, indexing
# the maildir becomes much faster since it's not opening any of the mail files.
# This could be useful if your IMAP clients access only new mails.

#mail_cache_fields = MessagePart

# Space-separated list of fields that Dovecot should never set to be cached.
# Useful if you want to save disk space at the cost of more I/O when the fields
# needed.
#mail_never_cache_fields = 

# Dovecot can notify client of new mail in selected mailbox soon after it's
# received. This setting specifies the minimum interval in seconds between
# new mail notifications to client - internally they may be checked more or
# less often. Setting this to 0 disables the checking.
# NOTE: Evolution client breaks with this option when it's trying to APPEND.
#mailbox_check_interval = 0

# 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.
#mail_save_crlf = no

# Use mmap() instead of read() to read mail files. read() seems to be a bit
# faster with my Linux/x86 and it's better with NFS, so that's the default.
# Currently mmap()ing is forced with mbox - this is a bug and will be fixed.
#mail_read_mmaped = no

# Copy mail to another folders using hard links. This is much faster than
# actually copying the file. This is problematic only if something modifies
# the mail in one folder but doesn't want it modified in the others. I don't
# know any MUA which would modify mail files directly. IMAP protocol also
# requires that the mails don't change, so it would be problematic in any case.
# If you care about performance, enable it.
#maildir_copy_with_hardlinks = no

# Check if mails' content has been changed by external programs. This slows
# down things as extra stat() needs to be called for each file. If changes are
# noticed, the message is treated as a new message, since IMAP protocol
# specifies that existing message are immutable.
#maildir_check_content_changes = no

# Which locking methods to use for locking mbox. All of them are used by
# default. flock is ignored in systems which don't have it. Note that the
# order of fcntl and flock are important to prevent deadlocks if they're both
# also used by other programs accessing the mailbox. Dotlock file is always
# created first.
#mbox_locks = dotlock fcntl flock

# Should we create dotlock file even when we want only a read-lock? Setting
# this to yes hurts the performance when the mailbox is accessed simultaneously
# by multiple processes, but it's needed for reliable reading if no other
# locking methods are available.
#mbox_read_dotlock = no

# Maximum time in seconds to wait for lock (all of them) before aborting.
#mbox_lock_timeout = 300

# If dotlock exists but the mailbox isn't modified in any way, override the
# lock file after this many seconds.
#mbox_dotlock_change_timeout = 30

# If main index file is incompatible with us, should we overwrite it or
# create a new index with another name. Unless you are running Dovecot in
# multiple computers with different architectures accessing the same
# mailboxes (eg. via NFS), it's safe to set this "yes".
#overwrite_incompatible_index = no

# umask to use for mail files and directories
#umask = 0077

##
## Authentication processes
##

# You can have multiple processes; each time "auth = xx" is seen, a new
# process definition is started. The point of multiple processes is to be
# able to set stricter permissions to others. For example, plain/PAM
# authentication requires roots, but if you also use digest-md5 authentication
# for some users, you can authenticate them without any privileges in a
# separate auth process. Just remember that only one auth process is asked
# for the password, so you can't have different passwords with different
# processes (unless they have different auth methods, and you're ok with
# having different password for each method).

# Authentication process name.
auth = default

# Space separated list of wanted authentication mechanisms:
#   plain digest-md5
auth_mechanisms = plain

# Space separated list of realms with authentication methods that need them.
# This is usually empty or the host name of the server (eg.
# mail.mycompany.com).
#  - plain auth checks the password from all realms specified in here
#  - digest-md5 must have the password added for each realm separately, and
#    many clients simply use the first realm listed here. so if you really
#    need to add more realms, add them to end of the list.
#auth_realms =

# Where user database is kept:
#   passwd: /etc/passwd or similiar, using getpwnam()
#   passwd-file <path>: passwd-like file with specified location
#   static uid=<uid> gid=<gid> home=<dir template>: static settings
#   vpopmail: vpopmail library
auth_userdb = passwd

# Where password database is kept:
#   passwd: /etc/passwd or similiar, using getpwnam()
#   shadow: /etc/shadow or similiar, using getspnam()
#   pam: PAM authentication
#   passwd-file <path>: passwd-like file with specified location
#   vpopmail: vpopmail authentication
auth_passdb = pam

# Executable location
#auth_executable = /usr/libexec/dovecot/imap-auth

# Set max. process size in megabytes.
#auth_process_size = 256

# User to use for the process. Only shadow and pam authentication requires
# roots, so use something else if possible.
auth_user = root

# Directory where to chroot the process. Most authentication backends don't
# work if this is set, and there's no point chrooting if auth_user is root.
#auth_chroot = 

# Number of authentication processes to create
#auth_count = 1

# More verbose logging. Useful for figuring out why authentication isn't
# working.
#auth_verbose = no

# digest-md5 authentication process. It requires special MD5 passwords which
# /etc/shadow and PAM doesn't support, so we never need roots to handle it.
# Note that the passwd-file is opened before chrooting and dropping root
# privileges, so it may be 0600-root owned file.

#auth = digest_md5
#auth_methods = digest-md5
#auth_realms = 
#auth_userdb = passwd-file /etc/passwd.imap
#auth_passdb = passwd-file /etc/passwd.imap
#auth_user = imapauth
#auth_chroot = /var/run/dovecot/auth

# if you plan to use only passwd-file, you don't need the two auth processes,
# simply set "auth_methods = plain digest-md5"