There is no way to stop people from faking your email address. Of course, somebody has to know your address to fake it... but emails fairly useless if nobody knows your address
As for stopping the error, you can set up filter them as regular spam if the server was nice/evil enough to return the original content. Otherwise, I don't believe there's a reliable way of filtering out all the spambounces while not filteirng out the legit bounces from mail that you send. Of course, if you wish, you can filter all bounces (but that might be kinda bad...)
Unfortunately there is no way to prevent this (apart from preventing spammers getting your e-mail address in the first place). Recently it appears that spammers are more often using random real e-mail addresses as the return address.
i thought i'm gonna give the free trial a ride and see if it might help.
ChoiceMail is great and it has great reviews. It's a bit expenisve, but I got mine at 10% off. So check out Froogle, PriceGrabber and Deprice. The actual link is http://www.deprice.com/choicemailone.htm but I don't know if the offer is still good