Environment: Exchange 2007 SP2 on Windows 2008, Outlook 2007 on XP clients. Our OWA points to webmail.domain.com which is set on a load balancer. This LB then sends the request to one of 10 CAS servers in the same AD site. I'm getting an HTTP error when connecting intermittently, so looks like one of our CAS servers is faulty. On my XP client, I am connecting to http://webmail.domain.com/owa Questions: 1. Is there any way on the client to tell which CAS I'm connected to? 2. If I want to check IIS settings, do I check the "Exchange" virtual directory within Default Web Site once I know what CAS server is causing the problem?

Hi, 1. Is there any way on the client to tell which CAS I'm connected to? Check the certificate of the OWA. Right click the OWA page and choose properties. Then click Certificates. 2. If I want to check IIS settings, do I check the "Exchange" virtual directory within Default Web Site once I know what CAS server is causing the problem? No. We should check the 'OWA' virtual directory. To resolve the issue, you can try to remove OWA virtual directory and create a new one: http://technet.microsoft.com/en-us/library/bb124811.aspx Please remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread. Thanks Gen Lin-MSFT

Hi 1. If I go to Page > Properties and look at the certificate, it's issued to webmail.domain.com - not sure how I can check that for the particualar server? 2. Ok, so OWA virtual directory is used for Web Access, what is Exchange virtual directory used for?

Hi, 1. If I go to Page > Properties and look at the certificate, it's issued to webmail.domain.com - not sure how I can check that for the particular server? Try to check the Thumbprint number in the certificate properties. Each certificate installed on CAS server should have different Thumbprint number. 2. Ok, so OWA virtual directory is used for Web Access, what is Exchange virtual directory used for? This virtual directory is used by Outlook Web Access when accessing mailboxes on computers that are running Exchange 2003 or Exchange 2000. If your organization includes Exchange 2000 or Exchange 2003 mailboxes in addition to Exchange 2007 mailboxes, all users can access Outlook Web Access through the /Exchange virtual directory. The Client Access server will automatically redirect Exchange 2007 mailbox users to the /owa virtual directory. If the server that hosts the Client Access server role also hosts the Mailbox server role, users who use the /Exchange virtual directory will be redirected to the /owa virtual directory, which cannot be used by Exchange 2000 or Exchange 2003 mailboxes. If you must support Outlook Web Access access to Exchange 2000 or Exchange 2003 mailboxes, do not install the Client Access and Mailbox roles on the same Exchange 2007 server. Please remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread. Thanks Gen Lin-MSFT