When I asked my original question below, I should have been more specific. I will rephrase my question, however, I do wish to extend my thanks & appreciation to those who answered my question as previously written!
Please advise whether there is an upper age limit for pilots flying strictly air freight and/or for companies like FedEx, UPS, DHL, etc. that fly a mix of air freight, documentation, etc. flying on american (USA) flag carriers within the USA? and, whether it makes a difference if the same USA carrier flies out of the USA to another country such as Canada, Mexico, central America, south America, Europe, Asia, Africa, etc.? Does the US postal service its own fleet of aircraft, and, if so, does it have an upper age limit for flying US mail and/or parcels?
Prior question left here for reference only:
(Please advise if there is an upper age limit for pilots flying aircraft carrying only freight (not passengers) into and out of the USA?)