> I see that spamassin has this feature. Just a side note: The larger and more diverse your user base, the worse off SA is. I tried it, and could not get it to the point where the spam outweighed much of the newsletters my users both read and write.
I am certain that with more work and configuration it would eventually have done great. The problem then becomes was it worth the time investment, and for me the answer was no. --Eric
