Mailing Items to Your Ultimate Duty Station
You are allowed to mail goods to yourself via USPS. When doing so, you should save the receipts and include them in your first travel claim after arriving in-theater. Per the Joint Federal Travel Regulations (JFTR), Chapter 5, Part D, you are entitled to reimbursement up to the cost that it would have cost the DoD to ship the equivalent weight, capped by the weight limit commensurate with your rank and orders.
However, before shipping yourself goods, it is highly advisable that you first get settled into your BOG job. In some environments or billets, it may be impractical to be responsible for a lot of personal gear.