Our receive connector is on our "Exch2010 box". However, when I unplug our "Exch2007 box" no emails arrive and cannot see Exchange. On 2010 - Exchange Management Console, Mailbox, "Exch2010 box" Properties, System Settings, "Domain controller servers being used by Exchange" = "Exch2007 box". How to I change this setting? I am guessing this is what I need in order to retire Exch2007 box.
Note: Server2008R2 running Exchange 2010. Server 2008 Standard SP2 x64 running Exchange 2007 (old box to bin). All mailboxes have been moved to "Exch2010 box". Also have similar issue at a client site but with same version of Exchange 2007 so would like to know what I have missed during migration. Both servers are DCs and are GC.