[1-26-20] Media Mail and Library Mail pieces bearing only postage stamps as postage payment and that weigh more than 10 ounces, or measure more than one half-inch in thickness, may not receive pickup service, nor be deposited into a collection box, Postal Service lobby drop, Postal Service dock, customer mailbox, or other unattended location. The sender must present such items to an employee at a retail service counter in a Postal Service facility. Improperly presented items will be returned to the sender for proper entry and acceptance.