I had my Lattissima (unboxed) in a carry-on and it was totally fine. Which magimix model do you have? The le cube is tiny so you should be OK, if you take it out of the box; not sure about the other ones. Just wrap it in bubble wrap or something so the exterior doesn't get scratched.

You could check it in, but you'd probably get condensation on the inside of the machine. In that case just leave it alone for a couple of days before using it.