I installed a new Exchange 2007 server into my Exchange 2003 environment with the hub transport and client access roles. I want this 07 machine to be responsible for sending all outgoing email from my organization.
Right after installation of the 07 server, email connectivity is still working, however the email is all going out my old 03 server. In the EMC -> Organization Configuration -> Hub Transport I gave the existing SMTP Connector a cost of 2, and then created a new SMTP connector, to connect to the Internet, with a cost of 1, using DNS (MX) to for outgoing.
Now, any email I send out gets stuck in the outgoing queue on my new 07 server with the error:
451 4.4.0 Primary target IP address responded with: "421 4.2.1 Unable to connect." Attempted to failover to alternate host, but that did not succeed. Either there are no alternate hosts, or delivery failed to all alternate hosts.
As soon as I remove the new SMTP connector the emails all get sent immediately through the old one back through my 03 server.
Any advice is appreciated.