Greetings all, I am in the middle of an Exchange migration from 2007 SP3 RU 13 to Exchange 2013 SP1
There are 3 MBX/CAS 2007 hosts and 1 2007 Edge server. 1 MBX/CAS and the edge are Server 2008, other two are 2008R2. I have installed 1 CAS, 1 MBX, 1 Edge 2013 into the Organization. All three are Hyperv guests installed 1 to 1 on Server 2012 R2 hosts. All the pre-req's are done - OAB check, Certs with legacy, Internal/external urls, ext DNS working with new CAS beofre legacy swap. IPv6 is on but disabled via registry parameter on all 2007 mailbox servers. I have disabled the Receive connectors on the mailbox server as all messages were getting that were processed by the new MBX server were getting caught in the Queue with a 451 4.4.0 DNS error I tried bringing up the Edge connector to see if it was just an issue with the MBX config, but it exhibits the same behavior. It is not a time sync problem. The history as far as I have been told is that it was a migration from Groupwise to Exchange 2003 then upgraded to 2007 about 3 years ago. Is there something with the old default routing group getting in the way or should I be looking somewhere else?
