We had posted a question along the excate same lines last week. The result appeared to work, but unbenost to us at the time was that it only appeared to work. We created a new SMTP connector with a lower weight than the existing SMTP Connector. Emails were creating a queue to the outbound Domain and when that failed automatically routing through the existing smart host. Not what we need.
Anyway we are reopening this issue and have learned that we can disable outbound email by disabling the URL for the smart host.
If you have made this far here is what we have going on.
An SBS 2003 Exchange (SP2) has an existing SMTP Connectors the Original connector (weight 10) is using an Smart Host which we are trying to move away from. The New Connector (weight 5)
is using DNS to directly route traffic.
The New connector does not have any outbound authentication. Telnet tests to other email servers produce mixed results. It connects, but during test periodically comes back with syntax error on the To: part. Assume it is my error with syntax and not sure if this is sestimic issue.
To test we change the URL of the Smarthost and observe emails bunch up in the queues. not sure what else we can test.
Throwing it out to you. Thanks!