Martijn de Munnik put forth on 10/19/2009 6:59 AM: > On Mon, 2009-10-19 at 13:50 +0200, Martin Schiøtz wrote: >> Hi >> >> I'm configuring a simple postfix smtp-server that is only used for >> outgoing emails for lots of users. >> I want to do some simple spam checking with postfix. I was thinking of: >> >> rbl >> spf > > RBL and SPF are techniques only used for incoming mail.
Correct. And I'll add that just about all standard anti spam techniques are not only useless, but in most cases dangerous, when applied to outgoing mail streams. The only "sane" anti spam checking one can perform on outgoing mail is body content analysis with something like SpamAssassin. I sincerely hope you really, really, learn up on this before you implement your new outbound relay. It's possible you may end up blocking all outbound mail if you don't get this right. -- Stan
