If you are getting the following message on your work iPhone:
It is because you have an old account in your Mail app. After moving to Microsoft 365 we no longer use Active Sync or the native Mail app and instead use the Outlook app.
Here is how you stop receiving this notification:
- Open Settings
- Scroll down and open Mail
- Open Accounts
- Open your Exchange account.
- Scroll down to Delete Account and tap it. Then confirm with another Delete Account tap.