I built a new Exchange 2010 HTCAS server and a matching 2010 Mailbox server. I then created a new mailbox on that new 2010 mailbox server.
The problem is that when I try to connect to that new mailbox server I get an "untrusted cert" prompt in Outlook complaining that the cert is untrusted. When I go to view the cert, its the cert from the old 2007 CAS server.
I troubleshooted to find out where it was getting this from, and it appears to be because the first thing Outlook tries is the old Exchange 2007 SCP (the name of the old 2007 CAS server is shown in the image below)
So I've been reading online that the solution is to delete that old SCP, but I cannot do that. The reason is because the Exchange 2007 CAS server is being used by all the users still. There will be a gradual migration process during which some users will be on Exchange 2007 and some on Exchange 2010, so I can't break SCP for 2007 users.
I also read that I could delete all SCPs and just manually config all Outlooks to use the CAS server of my choosing... but I cannot resort to manual configuration of Outlook for clients. There are way too many of them.
Is there something else I can do to fix this? Thanks!