The U.S. Postal Service would like to warn people that only authorized U.S. Postal Service delivery personnel are allowed to place items in a mailbox. By law, a mailbox is intended only for receipt of postage-paid U.S. Mail.
Recently, there have been reports of people placing non-mail items that did not bear U.S. postage in local mailboxes. The U.S. Postal Service recognizes customers may place non-mail items into mailboxes as a convenient way of “dropping something off,” but those items may cause a smaller mailbox to become full. When a mailbox is full, Postal Service regulations say the letter carrier cannot place mail in the box.
Additionally, the Postal Service has received complaints of flyers without paid postage being placed in mailboxes. Though many may be unaware, it is important to know that this type of activity is illegal by federal law. It may seem to be an easy way to advertise, but only U.S. Mail delivered by authorized personnel may be placed in mailboxes.
“We know many customers might not object to having a particular item placed in their mailbox from time to time, but the reasons for restricting use of mailboxes is really two-fold,” said Postmaster Keith Jackson. “First, if there is not enough room in a mailbox due to unauthorized items, the Postal Service can’t deliver the customer’s mail. Secondly, the Postal Service wants to ensure the integrity of our customer’s mailbox. That’s why only Postal Service personnel are authorized to place mail in or remove mail from mailboxes. In fact, U.S. Postal Inspectors advise customers to report people going mailbox to mailbox who are not postal employees. It could be someone completely unaware of the statute placing advertisements, but it could also be someone trying to steal mail.”
"We recognize that, from time to time, the statute and the Postal regulations may cause conflict with some customers," the Postmaster continued. "When all factors are brought to their attention, however, we hope that the great majority of the public would agree that restricting mailboxes to U.S. Mail not only ensures customers receive their mail, but it also increases the security of the service."
The Postmaster noted an exception to the general rule: newspapers can be placed in mailboxes only on Sunday; a non-delivery day for the Postal Service. He additionally noted that a newspaper receptacle can be mounted on rural or curbside mailbox post or support.