Folgende Registry Einträge sind dafür nötig:

Windows Registry Editor Version 5.00

[HKEY_CURRENT_USER\Software\Microsoft\Office.0\Outlook\AutoDiscover]
"ExcludeScpLookup"=dword:00000001
"ExcludeHttpRedirect"=dword:00000001
"ExcludeHttpsAutoDiscoverDomain"=dword:00000001
"ExcludeHttpsRootDomain"=dword:00000001
"PreferLocalXML"=dword:00000001
"ExcludeSrvRecord"=dword:00000001
"ExcludeLastKnownGoodURL"=dword:00000001