Makes no sense.
You aren't delivering the mail. Someone else is doing it for you instead. So that...makes it...not "diablo'ish" (which, guys, is a horribly retarded word, why the apostrophe?).
As I said, it's just a feeling. I'd be totally ok if there would be a mail system in the game.
But on the other hand, I find the shared stash more convenient.
As for the Diablo'ish: I don't know dude. English is not my native language, I saw it like that everywhere else so I just assumed that was the way it's supposed to be written :(
Please don't mix up drugs: some effects can cancel others.