I received the above message when i upgraded my iphone yesterday using a backup of the old phone from the previous day.
Not to go into specifics on email addresses but I have one master email address that I use for core emails and should be the one sync'd to the iphone. I set this up and have had this account administered by Fasthosts for over 12 years on laptop, desktop
and iphone with no issues until yesterday.
The sevice has never specifically been associated with the Outlook Web App as noted in the fix message as I have been running a forwarding email address specific to my Office 365 / Cloud account (i use these forwarders for security and damage limitation pruposes). The system did identify there is a link between the two accoutns when loggin on but will only show me detail relating to this forwarded address and contains no information of reference to any mobile email devices, only the Desktop and Laptop.
So I am now in a position where my email wont sync with my mobile, am provided with no clear facility to be able to manage and remove any legacy devices and can find zero other means of fixing this problem . .
Any help gratefully received. Fasthosts are trying to replicate their end but as of yet i've had no answer. Thanks