RETURNADDRESS
Return address
In postal mail, a return address is an explicit inclusion of the address of the person sending the message. It provides the recipient with a means to determine how to respond to the sender of the message if needed. The return address need not include a sender's name, but should include address or P.O. box details in the same way as the delivery address should. The return address also enables to post office to deliver mail back to you that they could not deliver to your intended recipient. Such mail may thus become dead letter mail In some countries, the return address is conventionally located in the upper left hand corner of the envelope, card, or label. In the ...The above text is a snippet from Wikipedia: Return address
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