What should you do if you receive mail that doesn’t belong to you?

When you receive mail that doesn’t belong to you, the appropriate action is to write "return to sender" on the envelope and place it back in the mailbox. This process ensures that the postal service is notified that the addressee does not reside at your address, allowing the mail to be returned to its original sender. This method is encouraged as it maintains the privacy of the intended recipient while ensuring the mail is handled correctly according to postal regulations.

Taking the mail to the nearest post office is also a viable option in some situations, but it may not always be necessary. Writing "return to sender" is a more straightforward action that allows the postal system to efficiently redirect the mail without requiring a trip to the post office. Opening or discarding the mail, on the other hand, is against postal guidelines and can lead to privacy violations or the loss of important correspondence.