I sold a book on ebay, and shipped from here to Texas. With Delivery Confirmation. Within a week the package was 'Out For Delivery'.
In Alaska.
The buyer was irate as all get-out, and demanded I refund his money. I said I don't own the USPS and cannot do anything about it. And in Alaska it languished for 6 weeks. Eventually, it was returned to me, with a note in it saying the address the PO was trying to deliver it to was not a valid one.
I contacted the buyer with said address, and he replied, "Oh, yeah, I worked in Alaska for two years, and that was my forwarding address." So the idiot never bothered to contact the PO and let them know he was back in Texas.
Yet, of course, it was all my fault according to him. He said I should have sent it to his Texas address. I sent him a photo of the package with his Texas address on it, along with a note "How would I know what your temporary address in Alaska would have been? I shipped it to the Texas address that I got from PayPal, which they got from YOU."