Sun, 18 Nov 2007 14:49:16 -0500 from Sanford Aranoff
Because I get email saying that it could not be delivered.
Is this what one calls a worm?
You're making an assumption, which is that the bounce messages are
going where they should.
More likely, I think is that some spammer is forging your address in
the return address field of its spams. Add to that the fact that some
idiot sysadmins still send bounce messages to the From or Reply-to
address, even when the Received headers don't match, and you get
bounce messages for mail you never sent.
I don't know of anything you can do about of it, short of laboriously
researching the sysadmin of each system that sends you a bounce
message and telling them to configure their system properly.