How do I have more than one database for SASL authentication in Postfix?

Question

I currently have Postfix set up to authenticate submission with SASL. The database connection info is stored in /etc/postfix/sasl/smtpd.conf

However, I cannot for the life of me figure out how to have TWO databases it should check for valid users. I am currently trying to host emails for different domains, and for security reasons they have to be in different databases.

How do I configure Postfix SASL to check more than one database?

I know there's an option for smtp_sender_dependent_authentication but I can't figure out how to use it.

Answer 1

The easiest solution to this was to just set Postfix to use Dovecot for authentication. It was much easier to have Dovecot configured for multiple databases than Postfix.