Why are you even concern about it? Unless you have friends that are members of the norther Mississippi flying club and you are directly targeting FedEx, this is a non issue. About your address, what address did you give when you applied for your job, license, medicals? What address does your company has on file as your address, what address is on both your FAA & CAA licenses? I guess that is your address then! You are over thinking it, besides, how long you think the USPS will be around for? That will go the way of the typewriter soon I suspect.