Exim and Dovecot SASL

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

conf.d/10-master.conf

service auth {
...
#SASL
  unix_listener auth-client {
    mode = 0660
    user = mail
  }
...
}

conf.d/10-auth.conf

auth_mechanisms = plain login

exim.conf

Create authenticators for Dovecot:

dovecot_login:
  driver = dovecot
  public_name = LOGIN
  server_socket = /var/run/dovecot/auth-client
# 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-client
  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 2