Start by opening Outlook
Click on the File tab
Click on Account Settings
Highlight your Microsoft Exchange account and click Change...
Click More Settings...
Click the Advanced tab
Type in the full email address of the shared mailbox and click OK.
The mailbox should now be added to your list.
Click OK, Next, Finish, and Close
Login to OWA using your own account - http://mymail.rit.edu/
Click on your name in the upper right-hand corner.
Enter the full email address of the shared mailbox in the Select mailbox: location and click Open.
You should now see the shared mailbox.