SQLGrey is a greylisting postfix policy daemon capable of using MySQL and 
Postgresql as backands. Its rather featureful too.

Linky:

http://sqlgrey.sourceforge.net/

Download link:
http://optusnet.dl.sourceforge.net/sourceforge/sqlgrey/sqlgrey-1.6.8.tar.bz2

Thanks to anyone who imports this.

Petr