Ansgar Wiechers put forth on 9/15/2009 4:28 AM: > Then you can't avoid sending backscatter. Period. RFC 2821 clearly > states: > > | If an SMTP server has accepted the task of relaying the mail and > | later finds that the destination is incorrect or that the mail > | cannot be delivered for some other reason, then it MUST construct > | an "undeliverable mail" notification message and send it to the > | originator of the undeliverable mail > >> therefore I don't know what the best way forward would be? > > Maintain a recipient list.
This is your starting point: http://www.postfix.org/postconf.5.html#relay_recipient_maps This might be useful for AD/LDAP: http://www2.origogeneris.com:4000/relay_recipients.html Google for other solutions. Lots of info on this topic out there. FYI my Postfix MX is strictly an anti-spam/gateway server as well, and I use relay_recipients. Granted, I've got less than 100 valid email addresses that change rarely, but even if it were 100,000 it still wouldn't be that much trouble to maintain, assuming I have timely access to address adds/changes on the downstream MTA(s), which I do. -- Stan
