Hi, > My boss want to open like this > owa.mycompany.com > i have configure DNS for mx record (owa.mycompany.com) but i dont know > how to configure it like that or enter any host header in iis. You need to open the IIS Manager, then create a new "Web Site". When entering the IP address, also specify "owa.mycompany.com", port 80. Then open the properties of this newly created web site, and go to the "Home Directory" tab. Then redirect the URL to mycompany.com/exchange That should do it! best regards Mike