Does anyone know how to setup an SPN(Security Principal Name) for the Exchange 2007 Web Service? We are having a double hop issue and we need to forward the user credentials to the Exchange server. Web Server is on one box, Database Server is on another, and Exchange is on yet another box. The web app authenticates fine, but Exchange code is failing as the request is passed on using the IIS App Pool identity. Does anyone have any experience troubleshooting these types of issues? We are trying something like this except we want to use Exchange 2007 Web Services instead. http://technet2.microsoft.com/WindowsServer/en/library/e5d4cdbd-f071-4a1a-b24e-92713f7fafc11033.mspx Any help is appreciated. Cheers, ~ck