Articolo completo: http://www.msoutlook.info/question/278

Chiavi di registro da modificare:

Key location for Outlook 2013:
HKEY_CURRENT_USER\Software\Microsoft\Office\15.0\Outlook\Preferences
Key location for Outlook 2010:
HKEY_CURRENT_USER\Software\Microsoft\Office\14.0\Outlook\Preferences
Key location for Outlook 2007:
HKEY_CURRENT_USER\Software\Microsoft\Office\12.0\Outlook\Preferences
Key location for Outlook 2003:
HKEY_CURRENT_USER\Software\Microsoft\Office\11.0\Outlook\Preferences

Value name: DelegateSentItemsStyle
Value Type: REG_DWORD
Value: 1