I have a quick question about setting up a legacy namespace to support Exchange 2007/2010 coexistence. We basically plan to stand up 2010 SP3 alongside our 2007 SP3 organization and slowly migrate our users over to the new 2010 mailboxes. It looks we will need to go the legacy namespace route since CAS 2010 doesn't support rendering OWA for mailboxes sitting on 2007 mailbox servers, as I understand it.
My confusion deals with the certificate. Right now we have a SAN that we use with all of our exchange related hostnames. Do we have to add legacy.mail.your-domain.com to the SAN since we have two 2007 CAS servers that are publicly facing? Is it as simple as that? We were hoping to have everything coexist without having to mess with certs on our 2007 boxes. Can someone break this down for me?