Not sure if this is an apple problem or Exchange 2010! A Power fail caused the exchange server to crash leaving the mail database slightly corrupted. After repair all seemed well except 2 x iphone 6 not being able to receive mail. Calendar and Contacts were syncing ok. Tried deleting accounts on the phone and re-adding them but still nothing. I then tried adding the other iphone's account to each of the two phones and they mail synced ok on that account. For some reason I just cannot get the original exchange mail account to work on the their respective original iphones. It's as if the server is blocking the ID of the phone to their original account. Although that same ID is used for any additional account added to the phone so I'm a bit puzzled. Has any one else overcome this problem before?