Exim and Dovecot SASL

Exim v4.64+ users can use Dovecot SASL instead of Cyrus SASL for authenticating SMTP clients.

Configuration Example

dovecot.conf

auth_mechanisms = plain login

service auth {
  ...
  # SASL
  unix_listener auth-exim {
    # Exim requires legacy auth type until it gets updated
    type = auth-legacy
    mode = 0660
    user = mail
  }
  ...
}

exim.conf

dovecot_login:
  driver = dovecot
  public_name = LOGIN
  server_socket = /var/run/dovecot/auth-exim
  # setting server_set_id might break several headers in mails sent by
  # authenticated smtp. So be careful.
  server_set_id = $auth1

dovecot_plain:
  driver = dovecot
  public_name = PLAIN
  server_socket = /var/run/dovecot/auth-exim
  server_set_id = $auth1

If you are having problems with this not working, ensure that you are using version 4.72 or greater of exim. Previous versions of exim have trouble with the version of the protocol used in Dovecot v2.x.