Select ‘Accounts‘ from the ‘Mail‘ tab under the program menu after opening Apple Mail.
Click the ‘+‘ sign and then select ‘Exchange‘ as the mail type for both Exchange or Office 365.
Enter an account description, your email address and your password and click the ‘Sign In‘ button.
It may take a few minutes to verify, if it shows the spinning circle it means it hasn’t failed yet!
Select the apps you want to use in Apple Mail with this account and then click ‘Done.‘
Your mail account is set up and will show you the apps you selected earlier. You should be done!