I'm in the process of setting up an Exchange 2010 environment that runs along side an established Exchange 2007 environment. When setting up a new Outlook profile, AutoDiscover establishes the network connection and finds the server settings successfully, but fails to log on to the server displaying the error message "The connection to Microsoft Exchange is unavailable. Outlook must be online or connected to complete this action." After clicking OK, I'm prompted with Microsoft Exchange server and Mailbox dialog screen (see attached screenshots). This happens for mailboxes that reside in Exchange 2007 and Exchange 2010.
My setup for Exchange 2010 is as follows: 2 CAS, 2 HT, and 2 Mailbox server DAG. I have a Brocade hardware load balancer balancing the traffic between the two CAS servers. I have Client Access Array configured that points to the virtual IP address of the hardware load balancer for the two CAS servers. I also have the following registry keys configured on both CAS servers with static ports:
OWA works fine for the mailboxes I'm trying to configure through Outlook.