filtres in Roundcube

In main.inc.php, go to the plugin array and add ('mamangesieve').

Then you should have a filter entry in the preference menu. Have to configure Dovecot to have it usable.

Spamassassin

 systemctl enable spamd.service
 systemctl start spamd.service                                                                   
 systemctl status spamd.service

If I understand well, spamassassin just add a "spam" tag to the mail but do not remove nor move anything, which is good.

Dovecot

The filtering can be made by Dovecot

Amavis

Install amavis-new with yast. The config file is

 /etc/amavis.conf

I read "Just use amavis with postfix. Amavis will take care of spamassassin"

http://www.howtoforge.com/perfect-server-opensuse-12.1-x86_64-with-nginx-ispconfig-3-p4