Open up the Outlook application and navigate to Outlook > Preferences.
Select Accounts from the new window.
Click on Add Email Account.
Enter your email address and Continue.
In the next window, you’ll want to click Not IMAP/POP? in the top right.
Now select Exchange.
Enter your username, password, and server (backstage.<yourcompanydomain.com>), and click on Add Account.
Now you’re all set to use your Backstage Mail account in Outlook!