SqlGrey or PostGrey
I would think it a worthwhile addition to include SqlGrey or PostGrey into ISPC3.
SqlGrey is a Greylisting system based upon the Perl PostGrey.
SqlGrey also has an add-on GUI for a web interface to control the system.
Would really assist in handling the growing amount of Spam for ISPC3 users without requiring them to go through my HOWTO on the Tips/Tricks/Mods forum here.
ISPC3 on Debian! It's great!