Passwd-file

This file is compatible with a normal /etc/passwd file, and a password file used by libpam-pwdfile PAM plugin. It's in the following format:

user:password:uid:gid:(gecos):home:(shell):extra_fields

For a password database it's enough to have only the user and password fields. For a user database, you need to set also uid, gid and preferably also home (see VirtualUsers). (gecos) and (shell) fields are unused by Dovecot.

The password field can be in four formats:

password: Assume CRYPT password scheme.
{SCHEME}password: The password is in the given scheme.
password[13]: libpam-passwd file compatible format for CRYPT scheme.
password[34]: libpam-passwd file compatible format for MD5 scheme.

extra_fields is a space-separated list of key=value pairs which can be used to set various passdb settings and userdb settings. Keys which begin with a userdb_ prefix are used for userdb, others are used for passdb. So for example if you wish to override mail_location setting for one user, use userdb_mail=mbox:~/mail.

Empty lines and lines beginning with '#' character are ignored.

Multiple passwd files

You can use all the variables in the passwd-file filenames, for example:

passdb {
  driver = passwd-file
  # Each domain has a separate passwd-file:
  args = /etc/auth/%d/passwd
}

Parameters

scheme=<s>: Allows you to specify the default password scheme. The default is CRYPT. This is available only for passdb.
username_format=<s>: Look up usernames using this format instead of the full username (%u). If you want to enable user@domain logins but have only "user" in the file, set this to %n.
default fields= <var>=<value> ...: pass environment variables to post-login script (<var> converted to upper-case). <value> can contain dovecot variables.

For example:

passdb {
  driver = passwd-file
  args = scheme=plain-md5 username_format=%n /etc/imap.passwd
}
userdb {
  driver = passwd-file
  args = username_format=%n /etc/imap.passwd
  default_fields = local_port=%a
}

Examples

This file can be used as a passdb:

user:{plain}password
user2:{plain}password2

passdb with extra fields:

user:{plain}password::::::allow_nets=192.168.0.0/24

This file can be used as both a passwd and a userdb:

user:{plain}pass:1000:1000::/home/user::userdb_mail=maildir:~/Maildir allow_nets=192.168.0.0/24
user2:{plain}pass2:1001:1001::/home/user2