I've had several Outlook users come to me asking to recover messages they've just accidentally deleted. When asked, they confess to have used Shift-Delete (permanent delete). What to do?
Outlook has the feature of being able to Recover Deleted Items, but by default it is only active for the Deleted Items folder. All other folders show the selection under the Tools menu grayed-out.
Through the registry on a workstation, you can configure Outlook to allow Recover Deleted Items for any folder.
1. Exit Outlook (if open)
2. Launch the Registry Editor (regedit or regedt32)
3. Expand HKLM\Sofware\Microsoft\Exchange\Client\Options
4. In the right pane, if there is a DWORD entry named DumpsterAlwaysOn, skip to step 7
5. Go to Edit-->New-->DWORD Value
6. Without any spaces, type the name DumpsterAlwaysOn
7. Set the DWORD value to 1 (value of 0 disables the feature)
8. Exit the registry editor
9. Launch Outlook