1 - Open Apple Mail
Open the Apple Mail application.
2 - Microsoft Exchange
On the Apple Mail home page, click "Microsoft Exchange."
3 - Enter your email address
Next, enter your email address and optionally a description. Then click "Next."
4 - Sign in with Microsoft
A new window will open, asking if you want to sign in with Microsoft. Click "Sign in."
5 - Enter password
Next, enter your password and click "Next."
6 - Server Settings
Please complete/change the information entered. The following information is required to set up your Hosted Exchange Direct Setup mailbox in Apple Mail for iOS:
Server: at.exchangeserver.online
Domain: none / leave blank
Username: Your email address
Description: Optional
Then click "Next".
7 - Conclusion
Select the features you want to use. Then click "Save".
You can now access your emails.