Postmaster General’s obligations where duty payment refused

If the addressee of a postal packet addressed to this country refuses to pay any duty payable under the Customs Laws in respect of the goods contained in such postal packet, the Postmaster General may retain the postal packet and at the expiration of twenty-eight days from the date of the notification of the arrival of such postal packet sent to the addressee, send the postal packet to the Comptroller of Customs, or return it to the country of origin in accordance with conventional arrangements with the country of origin.