I believe there is an option for UPS, I remember reading something about it in an issue of Rocky Point Times a few months back.
I am sure if you were to contact them they would give you the details.
You might want to check with Hector at the Burrito Express... he may have some ideas, if you don't know about the Burrito Express... Hector goes to the boarder and brings our mail from the Lukeville Post Office, he also will send packages from here...