yeah I agree with @DogThatWentGorp@hexbear.net, I think thefts in the postal system are fairly rare and he could also pay for insurance if he were really worried
but, as Doggo Gorpo said, mishandling is the default for shipments in America. Everything gets put into boxes and then packed into semi trucks and every step of loading and unloading is basically someone paid 70% of a living wage to throw boxes into or out of, and i literally mean throw
I think as long as it's packaged in a box with VOID FILLING (packing peanuts, air packs, whatever) so that it CAN'T MOVE and then packed into another, larger box around it, with similar void filling, it would 100% be fine
you could probably pack it less securely but then it wouldn't be 100% fine