To get access to those emails, use your outlook Barracuda Archiver Search feature and search for email received or sent by email@example.com.
Step 1: Click on "Search Archiver"
If you don't find this feature on you Outlook please notify us by sending an email to firstname.lastname@example.org
Step 2: Log in with your credentials.
Step 3: The Archiver Search window will pop up.
Step 4: Either enter the user's email address in the "From..." box,
or "Sent To..." box.
Step 5:Then click on Search.
Step 6: The results will show up in the box down below.
And that's how you get access to other user's mailbox. (Please first contact IT department for permission.)