I'm very happy with dspam (http://dspam.nuclearelephant.com/ http://dspam.nuclearelephant.com/), and the Dovecot integration plugin (http://johannes.sipsolution

I'm very happy with dspam (http://dspam.nuclearelephant.com/ http://dspam.nuclearelephant.com/), and the Dovecot integration plugin (http://johannes.sipsolutions.net/Projects/dovecot-antispam http://johannes.sipsolutions.net/Projects/dovecot-antispam)