I often talk about Challenge Response spam filters because I wrote the first one. One complaint people make is that the filters will challenge even forged mail, causing a challenge to be sent to the forgery victim. While this is not a DOS attack window as some people believe (since you can as easily DOS the target directly as get others to do it for you) it does need more consideration.
However, there are some autoresponders who have no excuse in this, and it is them I am railing on today. With the latest worm program, I am getting "bounces" back from anti-viral mail filters which tell me, "The mail you sent contains a virus and was not delivered."
Of course I didn't send the mail, my address was forged. What bothers me is that the anti-virus program clearly knows there is a virus, and presumably then should know it is the sort of virus which puts in a fake address.
So why it feels the need to send an error to the address it knows is fake, I don't know. The bounces I can tolerate, the bouncing software has no way to know it was a virus, but the anti-virus software has no excuse.
Addon: I'm going to promote a note from the comments because naive me didn't think of it. The virus companies may be happy to send this "your virus was bounced" mail to the wrong address because it's an ad for their anti-virus service.