Exchange Client Login

Hi,
I have a user that gets his mail from an Exchange 5.5 server in a different domain (different from the one he logs into). He is using the SonicWall VPN client to connect to the remote network. Then he uses Outlook 2000 with the Exchange service. I have it working but every time you close Outlook and restart it, the Exchange Client prompts you for the Username/Domain/Password information. Does anyone know of a way stop it from doing this?

Thanks for any help,

Steve Poulin
White Flower Farm