No "message-id" in the Postfix response.

I am in the process of switching from a Amazon SES email service to a custom Postfix setup I made on an EC2.

In the past, I extended the "Swift_Events_ResponseListener" class and would read the response from SES. Searching for a "SES Message ID" that I would then use for tracking purposes (bounces, complaints, etc).

My new Postfix setup sends great but Im not receiving a "message-id" from the server in the response, only a "queue-id" which I have read is not the same thing and really isn't meant for tracking.

Not sure how to include the "message-id" in my response from the server, any ideas?

Thanks

Update: I am seeing now that I can set the "message-id" outgoing on my application server using the following.

// A unique ID (time for this example)
$id = time();

// Set the ID in a email address format.
Swift_Message->setId($id . '@example.com');

Then I simply set that ID directly after the send. No need for extending the Swift_Events_ResponseListener class.