I had a client ship an anniversary tier once and it went okay. She froze it, then shipped it overnight Fedex on dry ice, and it was fine when it got there. I personally wouldn't try it, but I guess it can work.
I think most places use FedEx, overnight and packed on dry ice. ive ordered cupcakes from cupcake stop to see how they did it. and it was like triple boxed and each cupcake had a sucker stick in the middle to keep it from getting smashed.
"I know God won't give me anything I can't handle, I just wish he didn't trust me so much." ~ Mama T