Mail Redirection

I have two mail redirections going at once now as I have moved so much in the last 6 mths. With Soap moving next week it'll be my third. After moving so much and now having to move office it's kinda funny. Luckily Soap doesn't own much crap so it's nice and easy.

What woudl happen if you had your mail redirected to one place then redirected back to the other. Would the letter just stay in this continous loop?

Also can you ask for letters to be delivered on certain dates far into the future. Like in Back to the Futre 2? If so do they charge extra? You could use the post office to hold onto stuff while you go overseas then get it delivered when you get back.

Note: that Back to the Future 2 was the only movie I owned as a youngn' and thus the movie I have seen more times than any other movie. It wasn't even a legit version. Justa dodgey copy from a family friend who had an illegal video copying shop in her spare room.