U.S. postal services at USAG Stuttgart consist of Army Post Offices (APOs, where you send mail) and Community Mail Rooms (CMRs, where you pick up letters and packages). Each residential installation has an APO and a CMR; they are co-located on all installations except Panzer.
To open a CMR mailbox, you need a copy of your orders and your DoD ID card. Boxes can be assigned either at the installation where you work or where you live. Be sure to in-process with your CMR team on arrival and out-process when leaving the community for your next assignment. Your sponsor should be able to start the assignment process for your box even before you arrive.
Since postal services are a logistical entitlement, you will be required to show a valid DoD ID card anytime you mail something from an APO or pick up a package from a CMR. Mailing anything other than paper requires a customs form which can be created online prior to visiting the APO. If you encounter any issues, the APOs are also equipped with computers and helpful mail clerks. Using click-and-ship services – where you can pre-address, pre-pay, and enter customs data for your package at home – is highly recommended and saves time at the post office, since these mailings take just seconds to accept at the APO. Each installation also has blue USPS mailboxes in which you can deposit regular stamped letter mail. Letters can be mailed to German addresses using these drop boxes and a U.S. postage stamp if your CMR box is listed as the return address on the envelope.
When addressing things to a CMR box (with ‘APO, AE’ as city and state), ensure “Germany” is not written as part of the address. This could cause the item to enter the German mail system and cause delivery delays. Certain items are also prohibited to send or receive, such as medicines and supplements, alcohol, or coffee and coffee products. A full list of restrictions is available online and in postal facilities.
More information, including locations, days, and hours of operation at https://home.army.mil/stuttgart/index.php/my-garrison/all-services/mail