Hi,
We can try using the MFCMAPI tool to recover the folder. To do this, please follow:
1. Download and launch MFCMAPI tool.
2. Click Session > Logon, choose your profile name and click OK.
3. Double click on your mailbox from the list to open a new window.
4. In the new window, expand Root-Mailbox > IPM_SUBTREE and check if you have Deleted Items folder from the left pane. If so, select Deleted Items folder.
5. On the right, you should see the properties of the Deleted Items folder. One property it has is PR_ATTR_HIDDEN and it has a Boolean value. By default the value should be false. The folder is hidden as due to some reason the value changed
to true.
6. If the check box before Boolean value is selected, try untick the check and click OK.
7. Now, restart Outlook and then check if you can see the Deleted Items folder.
For detailed information, you can have a look at the following blog article:
http://blogs.technet.com/b/hitengiri/archive/2012/06/28/one-or-more-system-folders-missing-from-the-mailbox.aspx
Hope this helps.
Regards,
Steve Fan
TechNet Community Support