Users are core in dbmail, they decide where emails get delivered, users get access to their emails and can be given access to another user's email and also shared folders.


Managing users is easy with dbmail-users.

You can manage the following aspects of a user's account:

  • userid, the friendly name they use to authenticate themselves
  • password
  • email addresses (known as aliases)
  • mail quotas


The IMAP daemon dbmail-imapd uses login and cram-md5 authentication and validates the username and password.

You can choose to authenticate with sql database or ldap using the authdriver setting.

Access Control List

DBMail implements an earlier IMAP4 Access Control List (ACL) Extension (RFC 2086) and is aiming to implement 4314.

Database structure

  • dbmail_users
  • dbmail_aliases
  • dbmail_authlog
  • dbmail_usermap
  • dbmail_acl

DBMail User entitiy relationship diagram

A user is always created in dbmail_users even if they are authenticated using LDAP.

Table.Column Description
dbmail_users.user_idnr Primary key used as a foreign key to most of the tables
dbmail_users.userid Friendly username users use to authenticate themselves.
dbmail_users.passwd User's encrypted password
dbmail_users.encryption_type Type of encryption
dbmail_users.client_idnr Optional client reference
dbmail_users.maxmail_size Maximum email storage, see quota_failure in dbmail.conf
dbmail_users.curmail_size Current email size
dbmail_users.cursieve_size Current sieve size
dbmail_users.last_login Last login Enables or disables authentication for a user
dbmail_aliases.alias_idnr Primary key
dbmail_aliases.alias Email address
dbmail_aliases.deliver_to Used to identify user for delivery, dbmail_users.client_idnr
dbmail_aliases.client_idnr Optional client reference


DBMail is sponsored by