The U.S. used a cruise missile to deliver mail.

In 1959 the U.S. Navy submarine USS Barbero assisted the Post Office Department, predecessor to the United States Postal Service (USPS) in its search for faster mail transportation with the only delivery of "Missile Mail". On 8 June 1959, Barbero fired a Regulus cruise missile — its nuclear warhead having earlier been replaced by two Post Office Department mail containers — at the Naval Auxiliary Air Station at Naval Station Mayport. Twenty-two minutes later, the missile struck its target. The Regulus cruise missile was launched with a pair of Aerojet-General 3KS-33,000 [3 sec duration, 33,000 lbf (150 kN) thrust solid-propellant boosters. A turbojet engine sustained the long-range cruise flight after the boosters were dropped.

Upon witnessing the missile's landing,U.S. Postmaster General Arthur E. Summerfield stated, "This peacetime employment of a guided missile for the important and practical purpose of carrying mail, is the first known official use of missiles by any Post Office Department of any nation." Summerfield proclaimed the event to be "of historic significance to the peoples of the entire world", and predicted that "before man reaches the moon, mail will be delivered within hours from New York to California, to Britain, to India or Australia by guided missiles. We stand on the threshold of rocket mail."