On 09/10/2015 06:37 PM, Robert Chalmers wrote: > I’m currently running postscreen, and am wondering how I would add > spamassassin to the main.cf configuration, or are they mutually > exclusive?
In spite of what others have said, you can certainly use them together and many many installations do exactly that. Postscreen is a lightweight triage server that sits in front of postfix and will get rid of the bulk of SPAM without hardly any impact on system performance. Spamassassin is more thorough and will get rid of most of the SPAM that postscreen misses. Because of the heavyweight nature of Spamassassin it helps quite a bit to cut back on its load by running postscreen first, then there is not anywhere near as many messages left for SA to have to process and you can cut back on required system resources significantly. Spamassassin then processes and gets rid of (most of) the rest of the SPAM that postscreen misses. What you don't want to do is run postscreen and postgrey on the same system. I see a lot of people make that mistake and it results in serious mail delays because messages end up being deferred twice (first by postscreen then by postgrey). I always suggest that people get rid of postgrey and just use postscreen in this case. Peter
