Important notice for iPhone and iPad users
Apple iOS11 mail app not be compatible with Microsoft email applications
September 20, 2017
If you are using the native mail app on your iPhone or iPad and upgrade to iOS 11, you may encounter issues.
How does this affect me?
Due to an incompatibility in the new release of iOS, users of the built-in Apple Mail app in iOS 11 may be unable to sync their Office 365 mailbox or login to their accounts. iOS 9 or 10 users are not affected.
What do I need to do to fix this?
Microsoft and Apple are working to resolve this issue and will post more information to the article, below, when it becomes available.