The main reason that I haven't installed it yet is because it looks like mail is filtered at deliver time. I actually want to have mail scanned at the time that it is received.
Here is the url: http://www.nuclearelephant.com/projects/dspam/index.html
I guess I should clarify my post above. Since I run my spam and virus checker, throught amavisd all mail is scanned before delivery. In fact mail that is being relayed to a different server is being scanned. From what I read, it looks like DSPAM runs as the user for whom the mail is being delivered to using there settings. I need to be able to run this as a single user for all of my mail.