Announced last April, the Beta Mailbox for OS X finally showed up today. But did you notice the title quotes? Because . Anyone can now download the app, but to start playing with the famous email client I need to receive a betacoin to unlock it. If you have not received such a “coin”, you can request one through the official website. THE The Verge already tested the app (video above) and showed some interesting features of the version that runs on Macs.