Two times within the last two years I have sent registered letters to recipients in the US, with international return receipt forms (international form C5 (warning - PDF 100k) - in my case the text is not English+French but German+French, of course. The French designations are standard to Universal Postal Union forms).
Both times to corporate addresses (this times to Yahoo! Inc. because e-mail to the address they gave me bounced). Both times I double-checked my address on the C5 form. Both times the return receipt did not return to me.
Is there a possible common cause? Did I miss something? (I assume the USPS does know how to handle return receipts as they also offer a domestic version).