To setup the Exchange mailbox in MacOS Mail app, use the following steps;
- Open the System Preferences app.
- Click on Internet Accounts.
- In the right side of the windows click on Microsoft Exchange.
- In the Microsoft Exchange dialog window that appears, enter the following;
- Your name in the Name field
- Your Exchange email address in the Email Address field
Then click the Sign In button.
- In the next dialog window that appears, click on the Sign In button. After a few moments, the dialog should change to show your Name and Email Address, and a field to enter a Password.
- Enter your mailbox password in the Password field, then click the Sign In button.
- After a few moments, you should see a new dialog window appear asking you to, Select the apps you want to use with this account. Depending on your preferences, you can select all the apps shown in the list by placing a tick in the checkbox to the left for any wish to use with the account. For synchronisation across all devices, it is usually recommended to at least check, Mail, Contacts, Calendars at a minimum. After you are done with selecting your apps, click on the Done button.
Once you are done, you can quit the Internet Accounts window and Open Mac.Mail app and after a period of time, depending on the speed of your internet connection, you will see your mailbox folders and messages start to appear.
Generally, on a good connection with at least 100mbps download speed, it may take up to 30 minutes the synchronise most of the messages.