Here is my /etc/dovecot.conf:

Thanks Again!!!

Dovecot configuration file

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

'#' 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 after each value, it's not required to uncomment

any of the lines.

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 pop3 pop3s

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

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 = log_path = /var/log/dovecot10

For informational messages, use this logfile instead of the default

#info_log_path = info_log_path = /var/log/dovecot10-info

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

format. #log_timestamp = "%b %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. 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/pki/dovecot/certs/dovecot.pem #ssl_key_file = /etc/pki/dovecot/private/dovecot.pem

ssl_cert_file = /etc/postfix/newcert.pem ssl_key_file = /etc/postfix/newreq. pem

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

give it when starting dovecot with -p parameter. #ssl_key_password =

File containing trusted SSL certificate authorities. Usually not needed.

#ssl_ca_file =

Request client to send a certificate.

#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

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.

http://wiki.dovecot.org/Rootless

#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.

http://wiki.dovecot.org/UserIds

#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 = 32

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_connection 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_connection 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_connection

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

Greeting message for clients.

login_greeting = LXDNET IMAP 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

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 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 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 =

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

namespace settings, you can do it by defining namespace sections:

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. default_mail_env 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.

#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

default_mail_env, 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 #}

Grant access to these extra groups for mail processes. Typical use would

be # to give "mail" group write access to /var/mail to be able to create dotlocks. #mail_extra_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 mail_debug = yes

Log prefix for mail processes. See doc/variables.txt for list of possible

variables you can use.

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

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 to shared

filesystems (NFS or clustered filesystem). #mmap_disable = no mmap_disable = yes

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

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. NOTE: If you use NFS, remember to change also mmap_disable setting! #lock_method = fcntl #lock_method = dotlock

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

Default umask to use for mail files and directories.

#umask = 0077

':' 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 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. #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 to wait between those checks. Dovecot is however able to use dnotify

and inotify with Linux to reply immediately after the change occurs.

#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 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

mbox-specific settings

Which locking methods to use for locking mbox. There are four 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.

lockf : May not exist in all systems. Doesn't work with NFS.

You can use multiple locking methods; if you do the order they're declared

in is important to avoid deadlocks if other MTAs/MUAs are using multiple

locking methods as well. Some operating systems don't allow using some of # them simultaneously. #mbox_read_locks = fcntl #mbox_write_locks = fcntl

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 = 120

When mbox changes unexpectedly we have to fully read it to find out what

changed. If the mbox is large this can take a long time. Since the change # is usually just a newly appended mail, it'd be faster to simply read the # new mails. If this setting is enabled, Dovecot does this but still safely # fallbacks to re-reading the whole mbox file whenever something in mbox isn't

how it's expected to be. The only real downside to this setting is that if

some other MUA changes message flags, Dovecot doesn't notice it

immediately.

Note that a full sync is done with SELECT, EXAMINE, EXPUNGE and CHECK

commands. #mbox_dirty_syncs = yes

Like mbox_dirty_syncs, but don't do full syncs even with SELECT, EXAMINE,

EXPUNGE or CHECK commands. If this is set, mbox_dirty_syncs is ignored.

#mbox_very_dirty_syncs = no

Delay writing mbox headers until doing a full write sync (EXPUNGE and

CHECK # commands and when closing the mailbox). This is especially useful for POP3 # where clients often delete all mails. The downside is that our changes # aren't immediately visible to other MUAs. #mbox_lazy_writes = yes

If mbox size is smaller than this (in kilobytes), don't write index files.

If an index file already exists it's still read, just not updated.

#mbox_min_index_size = 0

dbox-specific settings

Maximum dbox file size in kilobytes until it's rotated.

#dbox_rotate_size = 2048

Minimum dbox file size in kilobytes before it's rotated # (overrides

dbox_rotate_days) #dbox_rotate_min_size = 16

Maximum dbox file age in days until it's rotated. Day always begins from

midnight, so 1 = today, 2 = yesterday, etc. 0 = check disabled. #dbox_rotate_days = 0

IMAP specific settings

protocol imap {

Login executable location.

#login_executable = /usr/libexec/dovecot/imap-login

IMAP executable location. Changing this allows you to execute other

binaries before the imap process is executed.

This would write rawlogs into ~/dovecot.rawlog/ directory:

mail_executable = /usr/libexec/dovecot/rawlog

/usr/libexec/dovecot/imap

This would attach gdb into the imap process and write backtraces into

/tmp/gdbhelper.* files:

mail_executable = /usr/libexec/dovecot/gdbhelper

/usr/libexec/dovecot/imap

#mail_executable = /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 plugins. mail_plugins is a space

separated

list of plugins to load.

#mail_plugins = #mail_plugin_dir = /usr/lib/dovecot/imap

Send IMAP capabilities in greeting message. This makes it unnecessary

for

clients to request it with CAPABILITY command, so it saves one

round-trip.

Many clients however don't understand it and ask the CAPABILITY anyway.

#login_greeting_capability = no

Workarounds for various client bugs:

delay-newmail:

Send EXISTS/RECENT new mail notifications only when replying to NOOP

and CHECK commands. Some clients ignore them otherwise, for example

OSX Mail. Outlook Express breaks more badly though, without this it

may show user "Message no longer in server" errors. 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.

netscape-eoh:

Netscape 4.x breaks if message headers don't end with the empty "end

of

headers" line. Normally all messages have this, but setting this

workaround makes sure that Netscape never breaks by adding the line

if

it doesn't exist. This is done only for FETCH BODY[HEADER.FIELDS..]

commands. Note that RFC says this shouldn't be done.

tb-extra-mailbox-sep:

With mbox storage a mailbox can contain either mails or

submailboxes,

but not both. Thunderbird separates these two by forcing server to

accept '/' suffix in mailbox names in subscriptions list.

The list is space-separated.

imap_client_workarounds = outlook-idle delay-newmail }

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 or seen 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_no_flag_updates = no

Support LAST command which exists in old POP3 specs, but has been

removed

from new ones. Some clients still wish to use this though. Enabling this

makes RSET command clear all \Seen flags from messages.

#pop3_enable_last = no

If mail has X-UIDL header, use it as the mail's UIDL.

#pop3_reuse_xuidl = no

Keep the mailbox locked for the entire POP3 session.

#pop3_lock_session = no

POP3 UIDL format to use. You can use following variables:

%v - Mailbox UIDVALIDITY

%u - Mail UID

%m - MD5 sum of the mailbox headers in hex (mbox only)

%f - filename (maildir only)

If you want UIDL compatibility with other POP3 servers, use:

UW's ipop3d : %08Xv%08Xu

Courier version 0 : %f

Courier version 1 : %u

Courier version 2 : %v-%u

Cyrus (<= 2.1.3) : %u

Cyrus (>= 2.1.4) : %v.%u

Older Dovecots : %v.%u

tpop3d : %Mf

Note that Outlook 2003 seems to have problems with %v.%u format which

was

Dovecot's default, so if you're building a new server it would be a good

idea to change this. %08Xu%08Xv should be pretty fail-safe.

NOTE: Nowadays this is required to be set explicitly, since the old

default was bad but it couldn't be changed without breaking existing

installations. %08Xu%08Xv will be the new default, so use it for new

installations.

#pop3_uidl_format = %08Xu%08Xv

POP3 logout format string:

%t - number of TOP commands

%p - number of bytes sent to client as a result of TOP command

%r - number of RETR commands

%b - number of bytes sent to client as a result of RETR command

%d - number of deleted messages

%m - number of messages (before deletion)

%s - mailbox size in bytes (before deletion)

#pop3_logout_format = top=%t/%p, retr=%r/%b, del=%d/%m, size=%s

Support for dynamically loadable plugins. mail_plugins is a space

separated

list of plugins to load.

#mail_plugins = #mail_plugin_dir = /usr/lib/dovecot/pop3

Workarounds for various client bugs:

outlook-no-nuls:

Outlook and Outlook Express hang if mails contain NUL characters.

This setting replaces them with 0x80 character.

oe-ns-eoh:

Outlook Express and Netscape Mail breaks if end of headers-line is

missing. This option simply sends it if it's missing.

The list is space-separated.

#pop3_client_workarounds = }

LDA specific settings

protocol lda {

Address to use when sending rejection mails.

postmaster_address = postmaster@example.com

Hostname to use in various parts of sent mails, eg. in Message-Id.

Default is the system's real hostname.

#hostname =

Support for dynamically loadable plugins. mail_plugins is a space

separated

list of plugins to load.

#mail_plugins = #mail_plugin_dir = /usr/lib/dovecot/lda

Binary to use for sending mails.

#sendmail_path = /usr/lib/sendmail

UNIX socket path to master authentication server to find users.

#auth_socket_path = /var/run/dovecot/auth-master }

Authentication processes

Executable location

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

Set max. process size in megabytes.

#auth_process_size = 256

Authentication cache size in kilobytes. 0 means it's disabled.

Note that bsdauth, PAM and vpopmail require cache_key to be set for

caching # to be used. Also note that currently auth cache doesn't work very well if # you're using multiple passdbs with same usernames in them. #auth_cache_size = 0

Time to live in seconds for cached data. After this many seconds the

cached # record is no longer used, *except* if the main database lookup returns # internal failure. #auth_cache_ttl = 3600

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/domain to use if none was specified. This is used for both

SASL realms and appending @domain to username in plaintext logins. #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 character translations before it's looked up from databases. The

value contains series of from -> to characters. For example "#@/@" means

that '#' and '/' characters are translated to '@'. #auth_username_translation =

Username formatting before it's looked up from databases. You can use

the standard variables here, eg. %Lu would lowercase the username, %n would

drop away the domain if it was given, or "%n-AT-%d" would change the '@'

into # "-AT-". This translation is done after auth_username_translation changes. #auth_username_format =

If you want to allow master users to log in by specifying the master

username within the normal username string (ie. not using SASL mechanism's # support for it), you can specify the separator character here. The format # is then <username><separator><master username>. UW-IMAP uses "*" as the # separator, so that could be a good choice. #auth_master_user_separator =

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

Even more verbose logging for debugging purposes. Shows for example SQL

queries. #auth_debug = no

In case of password mismatches, log the passwords and used scheme so the

problem can be debugged. Requires auth_debug=yes to be set. #auth_debug_passwords = no

Maximum number of dovecot-auth worker processes. They're used to execute

blocking passdb and userdb queries (eg. MySQL and PAM). They're # automatically created and destroyed as needed. #auth_worker_max_count = 30

Kerberos keytab to use for the GSSAPI mechanism. Will use the system

default (usually /etc/krb5.keytab) if not specified. #auth_krb5_keytab =

auth default {

Space separated list of wanted authentication mechanisms:

plain login digest-md5 cram-md5 ntlm rpa apop anonymous gssapi

mechanisms = plain

Password database is used to verify user's password (and nothing more).

You can have multiple passdbs and userdbs. 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.

http://wiki.dovecot.org/Authentication

By adding master=yes setting inside a passdb you make the passdb a list

of "master users", who can log in as anyone else. Unless you're using

PAM,

you probably still want the destination user to be looked up from passdb

that it really exists. This can be done by adding pass=yes setting to

the

master passdb.

http://wiki.dovecot.org/MasterPassword

Users can be temporarily disabled by adding a passdb with deny=yes.

If the user is found from that database, authentication will fail.

The deny passdb should always be specified before others, so it gets

checked first. Here's an example:

#passdb passwd-file { # File contains a list of usernames, one per line #args = /etc/dovecot.deny #deny = yes #}

PAM authentication. Preferred nowadays by most systems.

Note that PAM can only be used to verify if user's password is correct,

so it can't be used as userdb. If you don't want to use a separate user

database (passwd usually), you can use static userdb.

REMEMBER: You'll need /etc/pam.d/dovecot file created for PAM

authentication to actually work.

passdb pam { # [session=yes] [setcred=yes] [cache_key=<key>] [<service name>] # # session=yes makes Dovecot open and immediately close PAM session. Some # PAM plugins need this to work, such as pam_mkhomedir. # # setcred=yes makes Dovecot establish PAM credentials if some PAM plugins # need that. They aren't ever deleted though, so this isn't enabled by # default. # # cache_key can be used to enable authentication caching for PAM # (auth_cache_size also needs to be set). It isn't enabled by default # because PAM modules can do all kinds of checks besides checking password, # such as checking IP address. Dovecot can't know about these checks # without some help. cache_key is simply a list of variables (see # doc/variables.txt) which must match for the cached data to be used. # Here are some examples: # %u - Username must match. Probably sufficient for most uses. # %u%r - Username and remote IP address must match. # %u%s - Username and service (ie. IMAP, POP3) must match. # # If service name is "*", it means the authenticating service name # is used, eg. pop3 or imap (/etc/pam.d/pop3, /etc/pam.d/imap). # # Some examples: # args = session=yes * # args = cache_key=%u dovecot #args = dovecot }

/etc/passwd or similar, using getpwnam()

In many systems nowadays this uses Name Service Switch, which is

configured in /etc/nsswitch.conf.

#passdb passwd { #}

/etc/shadow or similiar, using getspnam(). Deprecated by PAM nowadays.

#passdb shadow { #}

BSD authentication. Used by at least OpenBSD.

#passdb bsdauth { # [cache_key=<key>] - See cache_key in PAM for explanation. #args = #}

passwd-like file with specified location

#passdb passwd-file { # Path for passwd-file #args = #}

checkpassword executable authentication

NOTE: You will probably want to use "userdb prefetch" with this.

#passdb checkpassword { # Path for checkpassword binary #args = #}

SQL database

#passdb sql { # Path for SQL configuration file, see doc/dovecot-sql.conf for example #args = #}

LDAP database

#passdb ldap { # Path for LDAP configuration file, see doc/dovecot-ldap.conf for example #args = #}

vpopmail authentication

#passdb vpopmail { # [cache_key=<key>] - See cache_key in PAM for explanation. #args = #}

User database specifies where mails are located and what user/group IDs

own them. For single-UID configuration use "static".

http://wiki.dovecot.org/Authentication

http://wiki.dovecot.org/VirtualUsers

/etc/passwd or similar, using getpwnam()

In many systems nowadays this uses Name Service Switch, which is

configured in /etc/nsswitch.conf.

userdb passwd { }

passwd-like file with specified location

#userdb passwd-file { # Path for passwd-file #args = #}

static settings generated from template

#userdb static { # Template for settings. Can return anything a userdb could normally # return, eg.: uid, gid, home, mail, nice # # A few examples: # # args = uid=500 gid=500 home=/var/mail/%u # args = uid=500 gid=500 home=/home/%u mail=mbox:/home/%u/mail nice=10 # #args = #}

SQL database

#userdb sql { # Path for SQL configuration file, see doc/dovecot-sql.conf for example #args = #}

LDAP database

#userdb ldap { # Path for LDAP configuration file, see doc/dovecot-ldap.conf for example #args = #}

vpopmail

#userdb vpopmail { #}

"prefetch" user database means that the passdb already provided the

needed information and there's no need to do a separate userdb lookup.

This can be made to work with SQL and LDAP databases, see their example

configuration files for more information how to do it.

http://wiki.dovecot.org/AuthSpecials

#userdb prefetch { #}

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. Note that this user is NOT used to access mails.

That user is specified by userdb above.

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.

Note that valid_chroot_dirs isn't needed to use this setting.

#chroot =

Number of authentication processes to create

#count = 1

Require a valid SSL client certificate or the authentication fails.

#ssl_require_client_cert = no

Take the username from client's SSL certificate, using

X509_NAME_oneline()

which typically uses subject's Distinguished Name.

#ssl_username_from_cert = no

It's possible to export the authentication interface to other programs:

#socket listen { #master { # Master socket is typically used to give Dovecot's local delivery # agent access to userdb so it can find mailbox locations. It can # however also be used to disturb regular user authentications. # WARNING: Giving untrusted users access to master socket may be a # security risk, don't give too wide permissions to it! #path = /var/run/dovecot/auth-master #mode = 0600 # Default user/group is the one who started dovecot-auth (root) #user = #group = #} #client { # The client socket is generally safe to export to everyone. Typical use # is to export it to your SMTP server so it can do SMTP AUTH lookups # using it. #path = /var/run/dovecot/auth-client #mode = 0660 #} #} }

If you wish to use another authentication server than dovecot-auth, you

can # use connect sockets. They assumed to be already running, Dovecot's master # process only tries to connect to them. They don't need any other settings # than the path for the master socket, as the configuration is done elsewhere.

Note that the client sockets must exist in the login_dir.

#auth external {

socket connect {

master {

path = /var/run/dovecot/auth-master

}

}

#}

Dictionary server settings

Dictionary can be used by some plugins to store key=value lists.

Currently this is only used by dict quota backend. The dictionary can be

used either directly or though a dictionary server. The following dict block

maps dictionary names to URIs when the server is used. These can then be

referenced using URIs in format "proxy:<name>".

dict { #quota = mysql:/etc/dovecot-dict-quota.conf }

Plugin settings

plugin {

Here you can give some extra environment variables to mail processes.

This is mostly meant for passing parameters to plugins. %variable

expansion is done for all values.

Quota plugin. Multiple backends are supported:

dirsize: Find and sum all the files found from mail directory

dict: Keep quota stored in dictionary (eg. SQL)

maildir: Maildir++ quota

fs: Read-only support for filesystem quota

#quota = maildir

ACL plugin. vfile backend reads ACLs from "dovecot-acl" file from

maildir

directory. You can also optionally give a global ACL directory path

where

ACLs are applied to all users' mailboxes. The global ACL directory

contains

one file for each mailbox, eg. INBOX or sub.mailbox.

#acl = vfile:/etc/dovecot-acls

Convert plugin. If set, specifies the source storage path which is

converted to destination storage (default_mail_env).

#convert_mail = mbox:%h/mail

Trash plugin. When saving a message would make user go over quota, this

plugin automatically deletes the oldest mails from configured mailboxes

until the message can be saved within quota limits. The configuration

file

is a text file where each line is in format: <priority> <mailbox name>

Mails are first deleted in lowest -> highest priority number order

#trash = /etc/dovecot-trash.conf }