Over the weekend my company migrated to Exchange 2010 from Exchange 2003. We are in a period of a Split Brain DNS where both servers reside on the network at the same time. All of the users can receive emails from Outside and the users can email out however when we use our ERP system to email out it fails. All of our Fax/scanners also cannot authenticate and fail as well. Finally our website which relays through the old server also are not making it through.
All of the Public IP addresses have been changed to point to the new server and all of the records required to identify both servers on the internet as well as internally have been changed. I can get to OWA on both servers internally and externally however I cannot log onto the new server OWA but that is a another question.
How can I troubleshoot this? I have created a relay on the new Exchange 2010 server and added all the relays that were on the old server but that does not work, yet.