It's simple. Just write "Return to Sender" across the envelope and mail it back. Or, if you want to cause them more grief, open the mail and send the heaviest things you can mail back in all of the postage paid envelopes you find. This will end up charging the recieving end for the extra weight. Suggested return envelope stuffers include:
- folded newspaper pages
- small bolts/screws wrapped in paper or bubblewrap
- large quatities of tape
- laminated laminated laminated laminated laminate sheets
- developed photos from that camera you found in the park
- playing cards, glued together
Remember who you're messing with. If it has your return address on it or a customer tracking number, try not to piss off the wrong people. If it's from the Church of Scientology, just mail them some prozac or zanax. I hear that stuff's like kryptonite to them.