[Mimedefang] yet another spam filter

[kamal]

We have written a new spam filter based on MIMEDefang.

Website: http://www.security.iitk.ac.in/projects/zarc/

It is a server-based spam filter which filters spam on the basis of 
feedback from its users. It does NOT do content-based filtering, the 
parts of email that it takes into account are (primarily) the sender's 
domain and the Received headers.

It is a collaborative spam filter, in the sense that it relies on 
multiple users helping the system (and therefore each other) identify 
and filter spam. So it works better as the number of users grow. But it 
is effective even with a small number of active users, say 10.