Accessing a Shared Mailbox with Outlook for Windows

Open Outlook > File > Account Settings > Account Settings again.
The Account Setting dialog will open. Choose “Change.”
Click More Settings, then Advanced.
With the Advanced box open, click Add.
The Add mailbox window will open. Enter the name of the mailbox you want to add and click OK. Once the mailbox has been added click OK again. Click Next and Finish.
Close the Accounts Settings box.
The mailbox will display on the left side of Outlook.