I am trying to replace an existing qmail installation with postfix.
Qmail is currently authenticating outgoing smtp from users clients with a perl script. This script checks user's provided username+password performing a AUTH LOGIN check on another external smtp server.
If the remote server responds with 235 return code, the provided username/password are ok and user is authenticated for qmail as well.
From what I understand it is possibile to use Cyrus or Dovecot SASL libraries on postfix to authenticate users, is it possibile to configure saslauthd or any of those libraries to replicate the perl script behaviour?
Unluckyly I do not have any other kind of access to the external smtp server cointaining users and passwords, I only can test AUTH LOGIN on an smtp connection.