Bug:saveAsync modifies changeKey when there are no changes made
To get an id of a draft item, we always have to call saveAsync. This call modifies the ChangeKey even when we don't modify the message. This is a problem because Exchange synchronization approaches rely on the fact that ChangeKey changes ONLY when there are actual changes to the message. So clients end up pulling messages that they should not have pulled ( because ChangeKey incorrectly indicates a change ).