This documentation is for Dovecot v2.x, see wiki1 for v1.x documentation.

User database extra fields

A user database lookup typically returns uid, gid and home fields. Other possibilities are:

These fields can be returned the exact same way as uid, gid, home and mail fields. Below are examples for some user databases.

Overriding settings

Most commonly settings are overridden from plugin section. For example if your plugin section has quota=maildir:storage=1024 value and the userdb lookup returns quota=maildir:storage=2048, the original quota setting gets overridden. In fact if the lookup always returns a quota field, there's no point in having the quota setting in plugin section at all, because it always gets overridden anyway.

To understand how imap and pop3 processes see their settings, it may be helpful to know how Dovecot internally passes them:

  1. First all actual settings are first read into memory.
  2. Next if post-login scripting is used, it may modify the settings if wanted.

  3. Last all the extra fields returned by userdb lookup are used to override the settings. Any unknown setting is placed into plugin {} section (e.g. foo=bar will be parsed as if it were plugin { foo=bar }).

If you want to override settings inside sections, you can separate the section name and key with '/'. For example:

namespace default {
  inbox = yes

The inbox setting can be overridden by returning namespace/default/inbox=yes extra field.




user_query = SELECT home, uid, gid, \
  '*:storage=100M' as quota_rule, mail_plugins \
  FROM users WHERE userid = '%u'



user_attrs = homeDirectory=home,uidNumber=uid,gidNumber=gid,quotaDovecot=quota,mail_plugins


Below are examples that show how to give two userdb extra fields ("mail" and "quota"). Note that all userdb extra fields must be prefixed with "userdb_", otherwise they're treated as passdb extra fields.

user:{plain}pass:1000:1000::/home/user::userdb_mail=mbox:~/mail userdb_quota_rule=*:storage=100M
user2:{plain}pass2:1001:1001::/home/user2::userdb_mail=maildir:~/Maildir userdb_quota_rule=*:storage=200M