Hi, I have two sites. SiteA and SiteB. SiteA: - has separate servers for mailbox, cas, and hts roles SiteB:- mailbox, CAS, hts roles are installed on a single server. I have enabled form based authentication on SiteACAS1 server and have set integrated authentication for owa virtual directory on SiteBEXCH(has all three roles) server. The SiteBExch has internalurl set to https://sitebexch/owa Now the problem is, when I am trying to access a mailbox hosted on SiteB exchange server through SiteA CAS server, it is displaying below error. However, I am able to access the same mailbox through https://sitebexch/owa URL directly. Type https:// at the beginning of the address you are attempting to reach and press ENTER. HTTP Error 403.4 - Forbidden: SSL is required to view this resource. Internet Information Services (IIS) Any thoughts what could be the problem here? Looks like proxying is working fine but it is trying for http URL I guess. This may be due to the fact that siteB exch server is a cas plus mbx server. Thanks, SitaramThanks, Sitaram www.sitaram-pamarthi.com

What’s in the internal URL field on both servers (CAS)? Please check it via EMC/EMS Please verify if the certificates have been enabled IIS service on the both servers via EMS. Is there prompted warning window when attempting to access OWA on both sites? Please reproduce the issue and post the IIS logs on both servers (CAS) at here for analyzingJames Luo TechNet Subscriber Support (http://technet.microsoft.com/en-us/subscriptions/ms788697.aspx) If you have any feedback on our support, please contact tngfb@microsoft.com

Looks like it's a transient issue. It got fixed after the server reboot. Thanks for your help.Thanks, Sitaram www.sitaram-pamarthi.com