title: How to display delivered and read receipts in MQTT broker Mosquitto?
body: <p>I want to display delivered and read receipts to users in my messaging platform. I am using Eclipse's Paho library with Mosquitto as the broker. Since Mosquitto does not store messages, which is the best way/plugin to </p>
  
  <ol>
  <li>Display <strong>delivered receipts</strong> - how to use QoS2 acknowledgement receipts to do this?</li>
  <li>Display <strong>read receipts</strong> - suggest me way to do this</li>
  <li>How to store messages so that users can view their <strong>chat history</strong>? Any architectural insights in mysql will be very helpful.</li>
  </ol>