That really depends on the APO.
Priority Mail Express generally is delivered the next business day.
Certainly.
Because all mail destined for APO/FPO addresses is sent priority (or should be, to almost guarantee delivery) it would depend on size + weight of the mail being sent. You can ship to APO/FPO via regular USPS mail, but again, it depends on your size and weight of the item being sent. If it's just a letter, you should be okay with just a regular stamp of the current stamp price.
An APO address is a military base somewhere in the world? Your ship stuff just as you would to any other address.
Typically, it will take 2 to 3 days for a priority mail package to ship from Michigan to Seattle. You can also upgrade to Express Mail which takes 1 day for shipment.
It isn't a country. The APO (Army Post Office) is a centralized location. Then, based on the unit, the mail is forwarded to the appropriate location. This allows someone to send mail without worrying about the unit being moved constantly. It also protects the location of the unit to prevent hostile governments identifying units. The biggest challenge is to the FPO (Fleet Post Office) which has to know ship movements to get the mail to the right part of the ocean!
APO = Army Post Office FPO = Fleet Post Office, they are how most military personnel get their mail.
Is this a chicken or the egg question? There was no pony express before horses.
APO AP 96367 is a US Postal Service address for U.S. military mail to Kadena Air Base, Kadena, Japan.
Royal Mail Ship, usually seen in its abbreviated form RMS, is the ship prefix used for seagoing vessels that carry mail under contract by Royal Mail. They have the right to fly the pennant of the Royal Mail when sailing.
You would have to have their FPO address. The US Military uses APO (Army Post Office) and FPO (Fleet Post Office) to deliver mail. This allows you to send mail to military people without knowing where they are, preventing the enemy from knowing about troop locations and movements.