Inside outlook select 'File' then account Settings' then on the Email tab click “New”
Click Account Settings -> Account Settings
On the “E-mail” tab, select your account and click on “Change”
Then on the next screen click “More Settings.” Select the “Advanced” tab.
Next, click “Add” and enter the name of the email account or shared mailbox.
Hit “Okay” then “Next” then “Finish”
You can find your new email box in your Outlook Inbox. Simply expand the selected email boxes as necessary.