We ship to PO Boxes (P.O. Boxes) all the time, but shipping to a one may delay processing as we sometimes have to verify the order. Keep in mind that FedEx is NOT available for PO Box delivery; if you want your order sent Express, the only choice is USPS Express Mail if you can’t provide a street address, which isn’t a guaranteed overnight delivery option to all addresses.
In other words, all PO Box orders will ship using the United States Postal Service, sent as Priority Mail or Express Mail, depending on the option you choose. Most places can receive U.S.P.S. Express mail these days, although FedEX guarantees overnight to almost every place on the planet.