## 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/

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

# 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. You can specify ports with
# "host:port".
#listen = *

# 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. 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/dovecot.pem
#ssl_key_file = /etc/ssl/private/dovecot.pem

# File containing trusted SSL certificate authorities. Usually not needed.
#ssl_ca_file = 

# Request client to send a certificate.
#ssl_verify_client_cert = no

# 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

# SSL ciphers to use
#ssl_cipher_list = all:!low

# Disable LOGIN command and all other plaintext authentications unless
# SSL/TLS is used (LOGINDISABLED capability). Note that 127.*.*.* and
# IPv6 ::1 addresses are considered secure, this setting has no effect if
# you connect from those addresses.
#disable_plaintext_auth = yes

# Use this logfile instead of syslog(). /dev/stderr can be used if you want to
# use stderr for logging (ONLY /dev/stderr - otherwise it is closed).
#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.
#log_timestamp = "%b %d %H:%M:%S "

##
## Login processes
##

# 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.
#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.
#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.
#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 = 16

# 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 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.
#login_max_logging_users = 256


##
## Mail processes
##

# Maximum number of running mail processes. When this limit is reached,
# new users aren't allowed to log in.
#max_mail_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

# Show protocol level SSL errors.
#verbose_ssl = 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

# ':' 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. See doc/configuration.txt for more information.
#valid_chroot_dirs = 

# Default chroot directory for mail processes. This can be overridden by
# giving /./ in user's home directory (eg. /home/./user chroots into /home).
#mail_chroot = 

# 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, 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 user there's no domain
#   %h - home directory
#
# See doc/variables.txt for full list. Some examples:
#
#   default_mail_env = maildir:/var/mail/%1u/%u/Maildir
#   default_mail_env = mbox:~/mail/:INBOX=/var/mail/%u
#   default_mail_env = 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 = 

# Workarounds for various client bugs:
#   oe6-fetch-no-newmail:
#     Never send EXISTS/RECENT when replying to FETCH command. Outlook Express
#     seems to think they are FETCH replies and gives user "Message no longer
#     in server" error. Note that OE6 still breaks even with this workaround
#     if synchronization is set to "Headers Only".
#   outlook-idle:
#     Outlook and Outlook Express never abort IDLE command, so if no mail
#     arrives in half a hour, Dovecot closes the connection. This is still
#     fine, except Outlook doesn't connect back so you don't see if new mail
#     arrives.
#client_workarounds = 

# 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

# Like mailbox_check_interval, but used for IDLE command.
#mailbox_idle_check_interval = 30

# 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

# Maximum allowed length for mail keyword name. It's only forced when trying
# to create new keywords.
#mail_max_keyword_length = 50

# 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.
# Note that OpenBSD 3.3 and older don't work right with mail_read_mmaped = yes.
#mail_read_mmaped = no

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

# Don't use fcntl() locking. Alternatives are dotlocking and other tricks
# which may be slower. Required for NFS.
#fcntl_locks_disable = no

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

# 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 messages are immutable.
#maildir_check_content_changes = no

# Which locking methods to use for locking mbox. There's three available:
#  dotlock: Create <mailbox>.lock file. This is the oldest and most NFS-safe
#           solution. If you want to use /var/mail/ like directory, the users
#           will need write access to that directory.
#  fcntl  : Use this if possible. Works with NFS too if lockd is used.
#  flock  : May not exist in all systems. Doesn't work with NFS.
#
# You can use both fcntl and flock too; if you do the order they're declared
# with is important to avoid deadlocks if other MTAs/MUAs are using both fcntl
# and flock. Some operating systems don't allow using both of them
# simultaneously, eg. BSDs. If dotlock is used, it's always created first.
#mbox_locks = dotlock fcntl

# 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

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

# 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

# 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

# Log prefix for mail processes. See doc/variables.txt for list of possible
# variables you can use.
#mail_log_prefix = "%Up(%u): "

##
## IMAP specific settings
##

protocol imap {
  # Login executable location.
  #login_executable = /usr/libexec/dovecot/imap-login

  # IMAP executable location
  #mail_executable = /usr/libexec/dovecot/imap
  # This would write rawlogs into ~/dovecot.rawlog/ directory:
  #mail_executable = /usr/libexec/dovecot/rawlog /usr/libexec/dovecot/imap

  # Maximum IMAP command line length in bytes. Some clients generate very long
  # command lines with huge mailboxes, so you may need to raise this if you get
  # "Too long argument" or "IMAP command line too large" errors often.
  #imap_max_line_length = 65536

  # Support for dynamically loadable modules.
  #mail_use_modules = no
  #mail_modules = /usr/lib/dovecot/imap
}
  
##
## POP3 specific settings
##

protocol pop3 {
  # Login executable location.
  #login_executable = /usr/libexec/dovecot/pop3-login

  # POP3 executable location
  #mail_executable = /usr/libexec/dovecot/pop3

  # Don't try to set mails non-recent with POP3 sessions. This is mostly
  # intended to reduce disk I/O. With maildir it doesn't move files from
  # new/ to cur/, with mbox it doesn't write Status-header.
  #pop3_mails_keep_recent = no

  # Support for dynamically loadable modules.
  #mail_use_modules = no
  #mail_modules = /usr/lib/dovecot/pop3
}

##
## Authentication processes
##

# You can have multiple authentication processes. With plaintext authentication
# the password is checked against each process, the first one which succeeds is
# used. This is useful if you want to allow both system users (/etc/passwd)
# and virtual users to login without duplicating the system users into virtual
# database.

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

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

# Space separated list of realms for SASL authentication mechanisms that need
# them. You can leave it empty if you don't want to support multiple realms.
# Many clients simply use the first one listed here, so keep the default realm
# first.
#auth_realms =

# Default realm to use if none was specified.
#auth_default_realm = 

# List of allowed characters in username. If the user-given username contains
# a character not listed in here, the login automatically fails. This is just
# an extra check to make sure user can't exploit any potential quote escaping
# vulnerabilities with SQL/LDAP databases. If you want to allow all characters,
# set this value to empty.
#auth_username_chars = abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@

# Username to use for users logging in with ANONYMOUS SASL mechanism
#auth_anonymous_username = anonymous

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

auth default {
  # Space separated list of wanted authentication mechanisms:
  #   plain digest-md5 cram-md5 anonymous
  mechanisms = plain

  # 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
  #   ldap <config path>: LDAP, see doc/dovecot-ldap.conf
  #   pgsql <config path>: a PostgreSQL database, see doc/dovecot-pgsql.conf
  userdb = passwd

  # Where password database is kept:
  #   passwd: /etc/passwd or similiar, using getpwnam()
  #   shadow: /etc/shadow or similiar, using getspnam()
  #   pam [<service> | *]: PAM authentication
  #   passwd-file <path>: passwd-like file with specified location
  #   vpopmail: vpopmail authentication
  #   ldap <config path>: LDAP, see doc/dovecot-ldap.conf
  #   pgsql <config path>: a PostgreSQL database, see doc/dovecot-pgsql.conf
  passdb = pam

  # User to use for the process. This user needs access to only user and
  # password databases, nothing else. Only shadow and pam authentication
  # requires roots, so use something else if possible. Note that passwd
  # authentication with BSDs internally accesses shadow files, which also
  # requires roots.
  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.
  #chroot = 

  # Number of authentication processes to create
  #count = 1

  # Require a valid SSL client certificate or the authentication fails.
  #ssl_require_client_cert = no
}

# PAM doesn't provide a way to get uid, gid or home directory. If you don't
# want to use a separate user database (passwd usually), you can use static
# userdb.

#auth onlypam {
#  mechanisms = plain
#  userdb = static uid=500 gid=500 home=/var/mail/%u
#  passdb = pam
#  user = dovecot-auth
#}

#auth ldap {
#  mechanisms = plain
#  userdb = ldap /etc/dovecot-ldap.conf
#  passdb = ldap /etc/dovecot-ldap.conf
#  user = dovecot-auth
#}

#auth virtualfile {
#  mechanisms = plain digest-md5
#  userdb = passwd-file /etc/passwd.imap
#  passdb = passwd-file /etc/passwd.imap
#  user = dovecot-auth
#}