We have Exchange 2003. I setup owa in our DNS with a Host (A) entry that has OWA.ourdomain.com pointing to our published IP for OWA. On our Exchange server under IIS, under Default Web Site Properties, Directory Security-Authentication and access control-Enable anonymous access checked and Integrated Windows authentication checked. I have created a Certificate pointing to owa.ourdomain.com. And I have checked Require secure channel SSL. Exported the Certificate. Restarted IIS services On our proxy server( ISA 2000) I have imported the Certificate in the Certificates snap in of MMC under Personal-Certificates and under Trusted Root Certification Authorities-Certificates. Under ISA management. I have Configured the listeners individually per IP address and added the the Server Certificate to authenticate to Web clients and Enabled SSL listeners. I also created a Destination set with the owa.ourdomain.com and paths /exchweb* , /public* and /exchange*. Created a Web Publishing rule point to this destination set. Under Binding I have checked the Require secure channel to published site. When I got to https://owa.mydomain.com/exchange, from out side my company, it ask me to accept our certificate the say page cannot be displayed. 500 Internal Server Error- The Target principal name is incorrect (-2146893022) Any Suggestions?