For the built-in Mail app to work for iOS you must be running iOS 11 or later. The Outlook app may be supported if your device cannot be updated to 11. Outlook is the preferred application for all devices where possible.
To check the version of iOS on your device, go to the Settings App and then go to General:
Then go to About:
Your iOS version will be listed beside “Software Version” (Version 11 or higher is supported).
