Pretty basic setup, I have a domain controller, Ex2007 server, and Ex2010 server. I have created a test account on the Ex2010 server, logged into OWA, and attempted to send a message to an external address and also to an address on the Ex2007 server. Neither of them are going through.
I also attempted to send a message from an account on the Ex2007 server to the test account on the Ex2010 server and it does not go through either. All services appear to be running properly on the 2010 server now and I have rebooted it since resolving some issues with the transport service not starting.