ROCKFORD, Ill. (WTVO) — You may receive flyers in your mailbox that have been delivered by salespeople or contractors, and not a U.S. Postal Carrier. Since mailboxes are considered federal property, is that illegal?

If you open someone’s mailbox with the intention of stealing, opening, or destroying mail, then you could be found guilty of a federal crime, with penalties of up to $250,000 in fines or up to 5 years in prison.

Federal law considers this crime the “Obstruction of Correspondence,” according to Legal Beagle. It is illegal to stop a letter from being delivered to its intended recipient.

Otherwise, there are no rules prohibiting you from opening someone else’s mailbox.

If, for instance, someone else’s mail is delivered to you by accident and you open it, that also doesn’t count as a crime if you reasonably believed the mail belonged to you, according to Garfinkel Criminal Law.

If you do receive mail that is not addressed to you, it is a federal crime to destroy it. It is also a felony if you know the person to who the mail is addressed, and you open and read it.

Experts advise instead that you should write something to the effect of “Addressee does not live here” on the envelope, and deposit it with your outgoing mail.