I tried to connect over RPC/HTTP with my notebook using Windows Vista Business and Outlook 2007. When I tried to connect I receive a window to insert username and password. But I am not able to connect to Exchange Server. Everything works fine when I am using VPN and local settings, OWA, OMA or my Smartphone connecting thru a an external WLAN. How do I have to configure Outlook or Exchange/ISA 2004?