If folders are not showing in the Microsoft Outlook desktop email client, but are visible in Outlook Web App (OWA) , the following two steps may resolve the problem:

1. Reset All Views in All Folders

1. Close Outlook
2. On your keyboard, click the Windows key + the R key to open the Run dialog box 
   
           + R
    
3. Type Outlook.exe /cleanviews then click OK
   
   
   
   
4. Outlook will launch; check for missing folders. If the problem is not resolved, please continue.

2. Clear and regenerate the Navigation Pane for the current profiles.

1. Repeat steps 1 and 2 above
2. Type Outlook.exe /resetnavpane then click OK

If neither of these options work, please open a ticket with the helpdesk. The next step will likely be to remove and re-add the mail profile via "Mail" in Control Panel.