Letters to SIT at Fort Benning 😔

My Soldier is at basic in fort benning and I've been sending him letters but it seems like he's not getting them 😕. I got a letter from him today stating that he hasn't received mail from me and that all the other soldiers have. Why are they taking so long? I live in North Carolina and the letter should've gotten to him already 🙁

Has this happened to anyone else??