How does one setup iMessage so that texts that come on my iPhone also are received on my Mac? I just assumed it would work fine with little to no setup. However even though almost all of my friends have iPhones/iMessage, I only get two or so people's imessages sent to my Mac. Why is this? Do they have to add my email or something? That would just be a pain in the ass. Please let me know what I have to do! Thanks!