§601. Letters carried out of the mail edit
(a) A letter may be carried out of the mails when—
(1) it is enclosed in an envelope;
(2) the amount of postage which would have been charged on the letter if it had been sent by mail is paid by stamps, or postage meter stamps, on the envelope;
(3) the envelope is properly addressed;
(4) the envelope is so sealed that the letter cannot be taken from it without defacing the envelope;
(5) any stamps on the envelope are canceled in ink by the sender; and
(6) the date of the letter, of its transmission or receipt by the carrier is endorsed on the envelope in ink.
(b) A letter may also be carried out of the mails when—
(1) the amount paid for the private carriage of the letter is at least the amount equal to 6 times the rate then currently charged for the 1st ounce of a single-piece first class letter;
(2) the letter weighs at least 12½ ounces; or
(3) such carriage is within the scope of services described by regulations of the United States Postal Service (including, in particular, sections 310.1 and 320.2–320.8 of title 39 of the Code of Federal Regulations, as in effect on July 1, 2005) that purport to permit private carriage by suspension of the operation of this section (as then in effect).
(c) Any regulations necessary to carry out this section shall be promulgated by the Postal Regulatory Commission.
§602. Foreign letters out of the mails edit
(a) Except as provided in section 601 of this title, the master of a vessel departing from the United States for foreign ports may not receive on board or transport any letter which originated in the United States that—
(1) has not been regularly received from a United States post office; or
(2) does not relate to the cargo of the vessel.
(b) The officer of the port empowered to grant clearances shall require from the master of such a vessel, as a condition of clearance, an oath that he does not have under his care or control, and will not receive or transport, any letter contrary to the provisions of this section.
(c) Except as provided in section 1699 of title 18, the master of a vessel arriving at a port of the United States carrying letters not regularly in the mails shall deposit them in the post office at the port of arrival.
§603. Searches authorized edit
The Postal Service may authorize any officer or employee of the Postal Service to make searches for mail matter transported in violation of law. When the authorized officer has reason to believe that mailable matter transported contrary to law may be found therein, he may open and search any—
(1) vehicle passing, or having lately passed, from a place at which there is a post office of the United States;
(2) article being, or having lately been, in the vehicle; or
(3) store or office, other than a dwelling house, used or occupied by a common carrier or transportation company, in which an article may be contained.
§604. Seizing and detaining letters edit
An officer or employee of the Postal Service performing duties related to the inspection of postal matters, a customs officer, or United States marshal or his deputy, may seize at any time, letters and bags, packets, or parcels containing letters which are being carried contrary to law on board any vessel or on any post road. The officer or employee who makes the seizure shall convey the articles seized to the nearest post office, or, by direction of the Postal Service or the Secretary of the Treasury, he may detain them until 2 months after the final determination of all suits and proceedings which may be brought within 6 months after the seizure against any person for sending or carrying the letters.
§605. Searching vessels for letters edit
An officer or employee of the Postal Service performing duties related to the inspection of postal matters, when instructed by the Postal Service to make examinations and seizures, and any customs officer without special instructions shall search vessels for letters which may be on board, or which may have been conveyed contrary to law.
§606. Disposition of seized mail edit
Every package or parcel seized by an officer or employee of the Postal Service performing duties related to the inspection of postal matters, a customs officer, or United States marshal or his deputies, in which a letter is unlawfully concealed, shall be forfeited to the United States. The same proceedings may be used to enforce forfeitures as are authorized in respect of goods, wares, and merchandise forfeited for violation of the revenue laws. Laws for the benefit and protection of customs officers making seizures for violating revenue laws apply to officers and employees making seizures for violating the postal laws.