Key: HKEY_CURRENT_USER\Software\Policies\Microsoft\Office\1x.0\Outlook\Options\Mail
or
Key: HKEY_CURRENT_USER\Software\Microsoft\Office\1x.0\Outlook\Options\Mail
DWORD: JunkMailImportLists
Value: 1
Note The 1x.0 placeholder represents the version of Outlook (11.0 = Outlook 2003, 12.0 = Outlook 2007, 14.0 = Outlook 2010, and 15.0 = Outlook 2013).
The JunkMailImportLists registry value is the trigger that is used by Outlook to determine whether junk email list settings are applied when you start Outlook. If this value is missing or is set to zero (0), Outlook does not apply any of the junk email list policy settings that may exist in the registry.