If you plan on sending mail to a soldier overseas, you must know exactly who you're sending it to. That's because both the military and U.S. Postal Service has banned mail addressed to "any service member".
The military is worried that the increased volume of letters over the holidays will overwhelm the military's mail system. Unsolicited mail also poses a threat to service members. Mail however is critical for morale and the Armed Services encourages e-mail.
If you want to send something to a loved one overseas for Christmas, time is running out. The deadline to mail by parcel post has passed, but you can still mail packages via "space available mail" if you get it to the post office by Saturday, November 27th. Parcel airlift must go out by December 4th. Any holiday cards or priority mail needs to be sent by December 6th. Express mail can go out as late as December 20th, but not all military units can receive express mail. Navy ships for example, do not have express mail services.
The Post Office recommends you write the service member's full name with or without rank, military organization or unit, and full APO or FPO address. Do not indicate the country of deployment.