- Ensure Outlook is the active application
- Click the Outlook menu (top left of screen) > Preferences > Accounts
- Select your Exchange account in the left column, then click Advanced
- Click into the Delegates tab then click the + button in the lower section labelled “Open these additional mailboxes:”
- Search for and select the Shared Mailbox you wish to add
Opening A Colleague’s Mailbox
The exact same steps as above will allow you to add another user’s mailbox if you have been granted permission to do so.