Chebyshev application allows someone to set up a spam filtering email forwarding service.
Chebyshev is an engine for an email forwarding service similar to those "firstname.lastname@example.org" email forwarding services that some schools provide. Combine email forwarding with spam filtering, and you have something useful. The chief design goal for this engine is simplicity.
This software expects to be installed on my computer which is a stock Intel based Red Hat Linux 5.1 machine, with apache-ssl installed and configured. Also, the machine assumes you have configured your mail transfer agent to utilize the Realtime Black Hole list; otherwise you just get forwarding without filtering.
For apache-ssl, please consult the web for installation instructions. My favorite source of cryptographically strong software is ftp://ftp.replay.com, a distribution site located in Holland. Please note that there may be patents, export regulations, and other legalities surrounding the use of cryptographic software in your location. Consult your local government for more information.
As for configuring your mail transfer agent, several agents are supported including Sendmail and Exim. Paul Vixie heads the Realtime Blackhole List; consult the web page at http://maps.vix.com/rbl/ for more details. Make sure you understand the implications of joining the Realtime Blackhole List; i.e. it can potentially block legitimate mail on occasion.
Once the preliminaries are in place, installation is fairly straightforward. Because this software is new, look over the Makefile before attempting installation. Then, as root, type "make install".