Tobacco products, and cigarette papers and tubes removed from a factory or an export warehouse, for export by parcel post to a person in a foreign country, Puerto Rico, the Virgin Islands, or a possession of the United States, shall be addressed and consigned to such person when the articles are deposited in the mails. Waiver of his right to withdraw such articles from the mails shall be stamped or written on each shipping container and be signed by the manufacturer or export warehouse proprietor making the shipment.