Hi allA bit of an unusual one here. We currently have an Exchange 2007 CAS server sitting behind a 3rd Party proxy server (WebSeal). For various reason there is a fairly complicated authentication process which results in the user being pre-authenticated by the proxy server and then trying to connect to the CAS server with a kerberos ticket (ie. Windows integrated auth).Now everytime I have ever configured Activesync (usually through ISA) I have just used the available authentication methods available in the Exchange Management Console which are Basic or Certificate Auth and not had a problem. An assumption has been made that because IIS which essentially hosts the Activesync Virtual Directory initiates the authentication and supports Windows Integrated authentication then kerberos authentication from the proxy to the CAS server should work as it does for OWA.As the Exchange server does not offer Intergrated Auth as an option though, I am not convinced. Can anyone shed some light on this or tell me categorically that integrated Auth will not work with Activesync?When preauthenticated by an ISA server which generally uses forms (so fall back to basic) what type of header is is then passed to the CAS server? Many Thanks Dan

Hi Dan Did you every get this working? Kind regards, Craig