Open Account Settings
With Outlook for Mac open, click on the Tools menu at the top of the screen, then choose Accounts.
In the Accounts menu, select "Delegation and Sharing"
Switch to the "Shared with Me" tab and click the plus (+) in the bottom left
Type in the email address of the delegate account you're trying to view, then click "Add"
It should now appear in the list. Once you click "Done", you should be able to see the inbox appear.
