We have a number of users that are having problems with ActiveSync, whereby mail doesn't fully sync or syncing is intermittent. The issue is only happening to a small number of users, isn't limited to specific devices or clients and when using multiple devices it can work ok on one but not the other.
One thing I've noticed is that the affected users all have mobile devices on their Exchange account which are corrupt/incomplete. The entries in Exchange for these devices show; FirstSyncTime, DeviceType, DeviceID, RecoveryPassword, Identity, IsValid and ObjectState. All other fields are empty.
If I delete all of the devices for these users in Exchange these corrupt/incomplete entries keep reappearing. I've tried everything I can think of including deleting from all devices in the Outlook app, removing Outlook from all their devices, repeatedly deleting. I even left the devices turned off and they still reappear.
From checking our web logs I can see ActiveSync requests for the corrupt/incomplete devices being received from Microsoft IP addresses which all get an HTTP 449 response. I am guessing these are what cause the corrupt/incomplete device entries. But I'm not sure why these requests would still be coming from Microsoft?
Any one got any ideas?
