Irrespective of phone, phone OS or type of email account one uses, this can and will happen when their is a sync error and an object becomes stuck in the out-bound queue of the device.
Periodically check the folders in the mobile mail client application's outbox for a hung item and manually remove it if one is found. This happens when sync objects cannot be reconciled and most often when replying to a received message that has more than one attachment of different types.
Just clear the offending object and you'll not see excessive data usage. This occurs, because Microsoft more fully and frankly, more properly sets its clients to "poll with the server", rather than according to an interval, or as new objects are sent "from" the mobile device. Ideally, remote clients, including mobile email clients, will poll with their hosts to ensure that all items remain identically synchronized - regardless of the number, type or mix of clients connecting to the same account/mailbox. While it enters an error state rarely, when it does, and the objects cannot be reconciled, the device will attempt to reconcile the object each time it polls with the host. Being unable to sync properly, a great deal more data is exchanged until the object is cleared.
|