I just encountered this issue. I use enterprise office356 using activesync services. I have been using this for many months but last week sudden i stopped getting email and after that i tried deleting my account and now i cant add my account back it gives this error.
When i contected my IT team they said no issue from server side and it works perfectly on other android devices and my Office365 account is also working fine. I haven't done any changes as well.
So i cleared the data and cache under both Email app and Exchange Services app and restarted the phone also but the error continues.
Also i notice when i type a wrong password, it tells me that the password is incorrect which means technically its reaching the server for authentication but afterwards some issue.
The company IT team is unable to help me further and seems like an issue at phone level. Any help is much appreciated, my last option would be to reset the phone / re-install but given the pain i like to try any other solution before.
Thanks,
uchi
