a postal receipt sent back to the sender of a piece of insured or registered mail on payment of a special fee that shows to whom and at what time the mail was delivered
https://www.merriam-webster.com/dictionary/return receipt

confirmare de primire ce constă în predarea către expeditor a dovezii privind predarea trimiterii poștale înregistrate
https://www.fancourier.ro/opod/