HowTo/PostfixAndDovecotSASL – Dovecot Wiki. Postfix and Dovecot SASL Since version 2.3, Postfix supports SMTP AUTH through Dovecot SASL as introduced in the Dovecot 1.0 series. If using Postfix obtained from a binary (such as a .rpm or .deb file), you can check if Postfix was compiled with support for Dovecot SASL by running the command: […]