You don't know what the terms of service are, but you signed a contract saying that you would abide by them? Hmmmm...
As I said in my original post, you can sync Exchange on the $30 plan (a plan which is, by the way, documented on the link I presented), but it's outside of the terms of service to do so. Therefore, whether or not you do it is not guided by any technical limitation. It is purely a decision of ethics.
Jim