After hours on line I found a solution which pointed to the inherited Active Directory permissions . You have to give/allow permissions to the "Exchange trusted subsystem" for the user in the Active Directory...
Hi team, i 'd like to share a solution which i have come across.
I work for an Automotive company (Boroko Motors Limited, Papua New Guinea) as an IT Support Officer and we have had issues getting the corporate emails set up on the newer iPhone models (6/7) as well as latest Samsung Galaxy phones.
When setup on the iPhone 6/7, it syncs no problem and sets up normally BUT when you open the email app you cannot view the mailbox folders (INBOX/SENT) and also send and receive emails, and you find in the email account settings the "Auto reply...Loading" and stuck there.
We had Exchange 2010 and recently migrated to 2013 and we have no issues setting up corporate emails on older phone models BUT we got stuck up when the staff switched to latest phone models.
We spent a great deal of time troubleshooting and concluded that new Email users created on Exchange worked perfectly, so that ruled out the suspicion that the newer phone models had a flaw - it is ONLY the exiting email users that had been migrated from the old Exchange that were having the problem ONLY on newer phone models (iPhone 6/7 and newer models of Samsung Galaxy).
After hours online i found a solution which pointed to the Active Directory permissions inherited. You have to give/allow permissions to the "Exchange trusted subsystem" for the user in the Active Directory...
Here is the link below for the FIX:
It definitely put to rest the issue of newer phone models(iPhone 6/7) not working.