backscatter (good one)
something i have been hearing a lot about lately (and it has happened to me) is you get up and fire up your email… suddenly you have a few dozen emails saying the note sent could not reach the recipient.
you look at the note, look at the user and scratch your head. “i did not send this, i don’t even know this person, what virus is on my PC?” not impossible, but likely backscatter (or blowback, collaterial spam or outscatter). the wikipedia page does a good job explaining this – but basically:
someone forged your email as the outbound message “envelope” when the email hits someone that is blocking or does not exist, the bounce comes to you 🙂 lucky!
there is no way to stop this, there is (generally) nothing wrong with your PC and many times you just have to ride it out – pressing the delete key many-a-time. just keep your ear on the ground…