Setup Form Authentication for Exchange 2003
1. install Certificate service
How To Set Up SSL Using IIS 5.0 and Certificate Server 2.0 http://support.microsoft.com/kb/299525
How to: Redirect an HTTP connection to HTTPS for Outlook Web Access (OWA) in Exchange 2003 Server.
http://www.microsoft.com/china/technet/prodtechnol/isa/2004/plan/owapublishing.mspx
How to set up Internet Security and Acceleration Server to host Web sites by using the Secure Sockets Layer protocol
http://support.microsoft.com/kb/292569
How to configure a certificate for use with a Web publishing rule in ISA Server 2004
http://support.microsoft.com/default.aspx?scid=kb;en-us;838244