I always thought it was illegal for anyone but a USPS employee to put anything into a residential mailbox or mail slot, but apparently a mail slot in the door is fair game and free for anyone to use.
When I ever wanted to hand-deliver a letter or Christmas card to a friend or neighbor, I would put it under the doormat since I knew putting it in their mailbox was illegal, but if they have a mail slot in the door, that is apparently OK.
Here is one law:
18 U.S. Code § 1725 - Postage unpaid on deposited mail matter
Whoever knowingly and willfully deposits any mailable matter such as statements of accounts, circulars, sale bills, or other like matter, on which no postage has been paid, in any letter box established, approved, or accepted by the Postal Service for the receipt or delivery of mail matter on any mail route with intent to avoid payment of lawful postage thereon, shall for each such offense be fined under this title.
And here is a USPS FAQ on the matter:
https://faq.usps.com/s/article/Rest...to-a-mailboxQuote:
Restrictions for attaching flyers, posters, etc. to a mailbox
Guidelines governing placing any item into a mail receptacle.
Apr 7, 2020
Article Number
000006998
Customer Information
Can a flyer/envelope be put it in someone else's mailbox without being mailed? What if a stamp was placed on it?
No. Per Sect. 508.3.1.3 of the Domestic Mail Manual (DMM):
"No part of a mail receptacle may be used to deliver any matter not bearing postage, including items or matter placed upon, supported by, attached to, hung from, or inserted into a mail receptacle. Any mailable matter not bearing postage and found as described above is subject to the same postage as would be paid if it were carried by mail."
"Postage" is defined as: Payment for a delivery service that is affixed or imprinted to a mailpiece, usually in the form of a postage stamp, permit imprint, or meter impression.
Notes:
USPS regulations do not govern what can be placed in a mail slot on your door. This means that if a local business wants to put a flyer in the mail slot, they can do so.
For further questions (or to report occurrences) regarding flyers being placed into your mailbox without first going through the postal system, please refer to the local Post Office.
So a "mail slot" is not a "mail receptacle". If you didn't know, well now you know.
Posted 12/19/2025 2:27 pm
