And finally, upon receipt of message 2, the destination can now send back one final ack indicating that it received all three messages for this sequence.

After the first set of messages, notice how the destination sends back an ack indicating that it received messages 1 and 3 — the sender now knows that it needs to resend just message 2.

Property indicating the destination queue of the message. Typically used when reading response messages, or messages in machine journals or dead-letter queues.