I have a Dovecot IMAP server and a Postfix server on separate machines. The user information is stored in a MariaDB database that is replicated on both servers.
Postfix needs to authenticate outgoing mail against our valid user database. I believe this requires us to install a "dummy" Dovecot on the Postfix server so that Dovecot SASL can provide authentication to Postfix from the database.
I think Cyrus had a standalone Cyrus-SASL package, but Dovecot doesn't?
If I wanted to setup a Dovecot instance on the Postfix server just for the purposes of SMTP authentication, and not use it to handle any mail, what is the minimum configuration required to make that work?
Is the dovecot-common package (Debian) enough? Or do I need the full dovecot-imap package?
What protocols go in the protocols directive? Can you just make it "protocols = auth" to disable IMAP connections?