I have setup a new Exchange 2007 server to coexist with Exchange 2003. Everything works well with email (across the exchange orgs) and Outlook will autodiscover Exchange 2007 mailboxes. I tried to go in to OWA on the Exchange 2007 CAS server and it said you must use https://cas.domain.com/owa, so I changed to https://cas.domain.com/owa and it says page cannot bedisplayed. I can go in IIS and uncheck require SSL inOWAand it works perfectly under http://cas.domain.com/owaat that point. However I cannot get to the Free Busy schedule of Exchange 2003 user, but an Exchange 2003 user can get to the Free Busy schedule of an Exchange 2007 user. So I unchecked in IIS require SSL in EWS and then I can see the Exchange 2003 userFree Busy in the Exchange 2007 users calendar in OWA...but it still does not work in Outlook 2007. My setup of the CAS server are the defaults, I did not change certs and it is using the defualt cert that Exchange 2007 installs. Obvioulsy the services work without SSL, but for some reason it is not letting me access in web services for Exchange 2007 via SSL. Even when I do the autodiscover test it fails, but it will still find users with autodiscover when setting up Outlook. I have looked everywhere and tried about a million different things with permissions, unistalling, reinstalling, and you name it. Anyone ever encountered such an issue? I am sure it is one little setting somewhere that I am missing. Thanks for any help or suggestions. Cliff

I ended up generating a new CSR and buying CA cert and that fixed the problem. I am still not sure why the default cert did not work internally.