> -----Original Message-----
> From: Marilyn Davis [mailto:marilyn@deliberate.com]
> I get plenty of collatoral spam now and then when my address gets used
> to spam people. If some of it is from C/R systems, I haven't noticed
> because my delete button gets goin' pretty fast. But, I figure I can
> block it by keeping track of the messages I send and when an error
> message comes in response to nothing I sent, I know it's collateral
> spam.
That's the goal of Signed Envelope Sender. See section 2.7.3 of this page:
http://slett.net/spam-filtering-for-mx/collateral.html
I haven't tried it myself, but I'm told it can be fairly effective. It
breaks some mailing lists and can cause problems for roaming users, though.
