I am using this page as a primary resource for setting up a new Exchange 2010 CAS server in my Exchange 2007 environment: http://technet.microsoft.com/en-us/library/dd351133.aspx
This is a single-AD domain environment running two Exchange 2007 servers (1 Mailbox, 1 CA/HT).
I have the following servers:
PRODMAIL2 Exchange 2007 Mailbox Server
PRODMAIL3 Exchange 2007 CA/HT Server
PRODMAIL Exchange 2010 CA Server (will eventually be HT/MBX server as well)
I have the following Internet DNS records:
mail.company.com (IP of PRODMAIL3)
legacy.company.com (IP of PRODMAIL3)
exchange.company.com (IP of PRODMAIL - this record was primarily created for testing)
I have Exchange 2010 CAS server running successfully and accepting OWA connections. I understand from Microsoft that a 2010 CAS can't access 2007 Mailboxes directly (correct?). However, the 2010 CAS should redirect me to the 2007 CAS, which will in turn give me access to my 2007 mailbox. Internally, this works (with a certificate error) as the redirect tries to go to prodmail3.internal.company
.com. However, that same redirect obviously does not work from outside of the company.
I've seen other questions answered on EE that seem to indicate (similar to the 2003-2007 migration) that I do NOT need an Exchange 2007 CAS after my 2010 CAS is running. If this is true, life sure would be easier.
I've also found various pages online mentioning the -Exchange2003URL command, but I don't believe that applies as I have no Exch 2003 in my environment.
So my question, in brief, which I cannot find concisely answered on the Internet: How do I migrate my CAS from 2007 to 2010 so that it's largely transparent to the end users?