What legislation prohibits cigarette smokers and tobacco shipments in mail unless fitting certain exceptions?

The Pact Act is the correct legislation as it specifically addresses the shipping of cigarettes and tobacco products through the mail. This act was implemented to combat issues related to underage smoking and the illegal shipment of tobacco products. It prohibits the mailing of cigarettes and smokeless tobacco unless specific criteria are met, such as verifying the age of the customer and ensuring the seller is registered and compliant with state and federal laws.

The other options do not focus specifically on tobacco shipping regulations. For instance, the FDA Act primarily pertains to the regulation of food and drugs, including tobacco products, but does not directly address mail shipping practices. The Mail Safety Act, while it may involve regulations concerning mail safety, does not specifically target tobacco products. The Controlled Substances Act is geared towards regulating drugs and controlled substances rather than tobacco products. Thus, the Pact Act is the most relevant legislation regarding the mailing of cigarette and tobacco shipments under specific exceptions.