View Shared Mail Folders
This article applies to: Outlook 2016 for Mac
The following link will take you to a Microsoft help page:
But before you go, here's some additional information you may find helpful.
This set of steps will make another person's mail folder(s) available to you automatically, every time you use Outlook.
The other person must first grant delegate access or share their mail folder(s) before these steps will work.