Am 29.08.2014 um 01:33 schrieb Timothy Murphy:

I'm trying to clarify the various ways in which I could set up Postfix + Dovecot + SpamAssassin under CentOS-7, and I'd welcome any comments on the following remarks.

As far as I can see there are 3 standard ways of setting this up:

1. Use amavisd
2. Use dovecot + pigeonhole/sieve
3. Use spamass-milter

At present I'm following (2), but am thinking of going over to (1), since this seems simpler. (Amavisd wasn't available when I set up CentOS-7, so I didn't consider it then.)

It seems to me that (2) is using dovecot in a slightly odd way, since as far as I can see dovecot normally takes email from ~/Maildir/cur/ and then moves marked spam.

not dovecot related - it's a matter of reject or accept spam

you are talking about spam filtering and forgot to mention that in the subject - in general dovecot should not have to deal with the topic spam filer because it should not see it at all

I'm not quite sure if (3) is a genuine alternative, or if it is why it is not the standard?

define standard - but amavis or spamass-milter are not topic of your subject - in general if you service mail for others you need to reject spam or have to deliver it and so you need a before-queue or become backcatter if you drop it after accept

the drawback of a milter is that filtering happens while the dilvering client is still connected and you have limited ressources in most cases

with a well configured postscreen and RBL scroing that should not be a problem until you have a really lot incoming legit mail flow