Postfix greylisting policy service with auto-white-listing written in Perl with SQL database as storage backend. Greylisting stops 50 to 90 % junk mails (spam and virus) before they reach your Postfix server (saves BW, user time and CPU time).
Seems to be a problem if you try to enable the clustering option. :( Does anyone know how to fix this problem?? Nov 6 20:11:25 mta-0 sqlgrey: dbaccess: Using DBIx:DBCluster Nov 6 20:11:25 mta-0 sqlgrey: fatal: Can't locate object method "connect" via package "DBIx::DBCluster" at /usr/sbin/sqlgrey line 843.