I got a box we shipped back with "insufficient address" on it. Now, mind you it is addressed EXACTLY as it was on the paypal invoice. So, I don't really understand would could be insufficient about it, nor will the USPS be of any help since we did not purchase any of their costly "extra" services. They said I could take it to the post office and query them - I thanked them for being their usual unhelpful selves. I e-mailed the buyer only to have the e-mail bounce back. I'll just let him contact me when he realizes that his package hasn't arrived and then he can explain the address problem AND the bounced e-mail and if the explanations are reasonable I'll send the package again, as long as I can use the postage that's already on it - if his explanation is not reasonable I will refund his money and he can go buy it elsewhere.