Jackpot is a ready-to-run SMTP relay honeypot, written in pure Java.

By running a relay honeypot on your computer, you can make a contribution to the battle against spam email. Jackpot enables you to submit accurately-aimed complaints, with detailed documentation accessible via a built-in web-server.

Jackpot is very entertaining to run - you can watch spam getting logged and then blackholed in real-time. You can examine the envelope (HELO) commands used to submit the spam to Jackpot, which is not possible using a simple spamtrap address. The details of spam-runs are saved in comma-delimited files, which you can analyse using simple tools.

Jackpot can also store captured spam-data in a single database shared by a community of co-operating honeypots.

I am running this on www.e3.com.au for ports 1080 and 3128 but had to disable port 25 as I need email on that box. It actually is fun to watch spammers get tangled up!

Link: http://jackpot.uk.net