Note that this feature works only when you are using Exchange Server email account.
If you have permanently deleted items in outlook with shift-delete you can still recover them before they are fully send to the bit-heaven. Items remains in the Exchange server until the retention time for deleted items have elapsed. Retention time policy is configured in the Exchange server.
By a little registry tweak you can enable “Recover Deleted Items” command for any Outlook/Exchange folder. You can view and recover deleted items including the permanently deleted.
1. Exit Outlook
2. Open registry editor
3. Browse to \HKEY_LOCAL_MACHINE\Software\Microsoft\Exchange\Client\Options
4. Create new DWORD name it as DumpsterAlwaysOn and set it value to 1
5. Exit registry editor and restart Outlook.
Now you have the Recover Deleted Items… command in the Outlook’s tools menu.
P.S. I tried to recover items when Outlook was not connected to the Exchange and it totally crashed.