>> http://forum.qmailrocks.org/archive/index.php/t-1623.html >> >> I found the above link when looking for a how to for configuring postfix >> to bounce email BEFORE the initial MTA transaction is complete. I can't >> seem to find one for postfix. I want a sending MTAs to get a 550 error >> if spamc/spamd determine a mail is spammy so non spam senders get some >> sort of feedback that their message has been tossed and not delivered. >> For obvious reasons you can't do this as a bounce to the From: or >> Reply-To: header emails so it has to happen during the initial MTA >> transaction. Can someone point me to a how to for this? >> > > Unless I'm misunderstanding you, what you really want is to not accept the > message if it's spam. Bouncing it implies accepting it and then sending back > an NDR. > > Although you can accomplish this with a Before Queue Filter: > http://www.postfix.org/SMTPD_PROXY_README.html, it may become a performance > problem and it probably not an optimal solution. > > Aside from anything else, it will really annoy the senders if the mail is > legitimate. > > Terry > > Agreed, you would only want to run your before-queue configuration on a lightly loaded mail system, unless you can engineer a creative way of distributing the load.
However, I don't see how it would annoy the senders, unless something was configured poorly and you generated a lot of false positives.. If your FP potential is low, you would be just fine running this way. Rejecting messages inline is a far better solution than generating a bounce or simply dropping the message. Most, if not all spam has a forged sender so generating a bounce is a very bad idea. Rejecting inline is much better than dropping message; at least that way the sender will get an NDR from their MTA. -M
