Greetings, Reindi, search through postfix docs for that:
+ permit_sasl_authenticated + permit_mynetworks (play with the mynetworks definition, so, initially you allow all mail from your local network, and when *all* of your users moved to new authenticated schema, you just removed local network from here) That one is not so important, but I have found it really useful in my environment: + reject_authenticated_sender_login_mismatch (this is an interesting one, that you can later replace with: reject_sender_login_mismatch ... now, I use LDAP with all of this). I am a little in a hurry now, but if you read the docs you may get the idea. I hope this helps, Ildefonso Camargo.