At my school every person is issued an iPad 2 and iMessage was able to be used fine for the first two weeks but now disabled it some how not allowing anyone to use it when a message is sent the following error message is displayed "not delivered" I am positive it has nothing to do with my iPad this same message also appears I am looking for anyway to bypass this or any allternative to messaging with iPads without downloading any apps form the app store (we are aloud to download only specific apps)