I was wondering the web looking at random items, when I came along an article at http://www.worldwidecreations.com titled Stopping spam before the door with SpamCop and IPTables

Its a great article with a lot of information and code on how the author is able to grab the offending hosts and place them within IPTables.

This application suite is quite the AIO (All in One). I have used eGroupware, and was a joy. I was trying to find more projects to create in it than actually using it to manage them. This is defiantly an application you want to check out and play around with.

OfficeSpot.Net Collaboration Server Preview 2 (Default branch) - The OfficeSpot.Net Collaboration Server is a
one-stop solution for all your groupware needs. It
is based on Ubuntu 6.06 LTS and is preloaded with
eGroupWare, Postfix, OpenLDAP, MySQL, DBMail,
Spamassasin, and ClamAV.

License: GNU General Public License (GPL)

Changes:
This release contains updated versions of eGroupWare (1.4), DBMail (latest stable SVN revision), and ClamAV (0.90.3). The installation process was streamlined and the online documentation was updated.

[FreshMeat]