Agree with Tax-chick. I have gotten and used many addresses there, and received many replies.
I love reading the stories and viewing the pics the troops post there.
It’s also Cub Scouts popcorn time. If you see Cub Scouts or have one at the door, you can make a contribution in any amount to send popcorn to troops overseas. My daughter got some when her Coast Guard cutter was in port with Navy ships in Asia. (Coast Guard is Homeland Security, not Department of Defense, so they can get left out of things.)
That’s not the same as sending a personal letter, of course. You might also contact your local VFW or American Legion post. They are often in contact with people deployed from your local area.