Exchange email accounts associated with the users enrolled onto airwatch are unable to verify account information on iphone

[KSDE]

On a same iphone and a same email domain, I can setup an exchange email accounts that are not entered on Airwatch but if an email account is associate to a user enrolled on Airwatch, the iphone will give this error ' unable to verify account information' . I have Exchange ActiveSync profile setup on Airwatch. Does anyone know why?

[TristanDawson]

Have you got MEM configured to somehow block these users?
Or perhaps a config issue with the Exchange profile that's being deployed? We had a certificate error on our Android devices that needed an intermediate certificate to be deployed with the Exchange Profile...

[KSDE]

Thanks for your reply Tristan. Both Exchange Email and Airwatch together made things difficult. Settings change on Exchange email can affect all the device enrolled onto Airwatch. I have been ' trial and error'  on Airwatch settings for the last few days until I hit a success, it's the field ' user principle name'  need to be set to user's email address. I don't understand the reason why but it works.