Yes, return to sender... I agree, you've already gone above and beyond.
Tip: when RTS-ing, use a permanent marker to black out any barcodes (front or back, black or orange) that were printed on the envelope by the post office. I had a job for a year at a college dorm hall-desk, and a big part of our daily duties was sorting mail. This included forwarding, RTS-ing, or destroying mail addressed to former residents, depending on whether or not they left a forwarding address, how long ago they moved out, and the level of postage. (Presort Standard and the like--aka bulk or "junk" mail--don't get forwarded, unless there are forwarding instructions from the sender, because as I understand it the sender has to have paid extra for forwarding services. You can feel free to throw that out just as you would your own junk mail.)
Anyway, if we didn't black out those barcodes, even if we had crossed out the address and marked Return to Sender, sometimes the envelopes would come right back to us because they got routed based on the pre-existing barcodes, not what was written/stamped on the envelope. Granted, it's been about 5 years since I worked in that capacity, but I'm guessing it's still the same deal. Your postal carrier would probably catch it, but it might save him/her a step.
Last edited by badgercat; 12-01-2010 at 06:26 PM.
'09 Jamis Satellite Femme | stock Jamis Road Sport -- road
'08 Trek 7.2FX | Terry Cite -- commuter
'77 Raleigh Grand Prix mixte | stock Brooks (vinyl) -- just for fun!