For example, when I tried to verify this address through your website I got "invalid address error":
Street: Cmr 422 Box 1500 City: Apo State: Armed Forces Europe Postal Code: 09067
We certainly do. Within that CMR, I tested Box 1 through 2000 and here are the results:
VALID ADDRESSES 1-99, 101-199, 201-299, 301-399, 401-499, 502-599, 601-699, 701-799, 801-899, 901-999, 1001-1099, 1494
INVALID ADDRESSES 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1100-1493, 1495-2000
I didn't go any higher than 2000, but yes, we certainly do validate military addresses as well. At least as far as is possible. An active military command doesn't want you and I to know where they are, so their "home base" mailing address remains the valid address and the Military Postal service takes care of the forwarding and final delivery.
According to the USPS that box is not valid. This can be checked at any time using the official USPS Address Lookup tool. When you enter your address, the result is:
"Several addresses matched the information you provided. Perhaps you didn't enter a street number or the building has multiple units. "
Along with a list of the available ranges. I also included the ranges for you in the initial response. The US Postal Service doesn't perform address validation when they accept a parcel from you at the post office and they certainly don't if you just put a letter or small package in the mailbox at your house. The USPS likes to have addresses verified before shipment because it means fewer returns for them (lower costs). However, if you were to mail a letter to yourself and intentionally get the address wrong, (for example add one digit onto the number) it will likely still get to you due to the human nature of the final delivery team. If a letter is sent to PFC Jonathan Jones at CMR 422 Box 1500, the postal clerk at the delivering terminal might notice that the box is currently invalid but there is a PFC Jonathan Jones in box 1499 and deliver it there instead. The goal of all postal services is to get the mail to the right place. If it were just a computer, there would be a lot more mail returned to sender as undeliverable.
You can certainly use "Armed Forces Europe" as the state and our system will accept and standardize the input to "AE". You can check this anytime on our homepage with the sample lookup.