It may actually be impossible for the PlayBook to use Blackberry's email system. Is it possible that the lack of an email client on BlackBerry's PlayBook is due to the fact that it is impossible to do. A rumor reported by Business Insider says that RIM has to rewrite its entire messaging architecture to get email and messaging onto the flailing tablet.
The problem, according to a source who spoke to a director of BlackBerry product management, is that BlackBerry accounts cannot support more than one device.
Gadget Lab