title: How to check the delivery status of Firebase message sent to an Android application?
body: <p>I am testing the Firebase JSON to check the delivery receipts of the notification sent to the news app. I can successfully send the message to the Android app without any issues and I receive the message on my Android app. However, I want to know how and where can I check if the notification was successfully delivered to the Android app? </p>
  
  <p>How do I use the <code>message_id</code> and/or <code>multicast_id</code> that is given back to get the delivery status of the notification? I can't find working code examples of checking for delivery status with Firebase. Does anyone have working JSON code to query the delivery status of a Firebase message via the <code>message_id</code> and/or <code>multicast_id</code> or another way? The Firebase documentation does not give examples on how to do this (or maybe I missed the example).</p>
  
  <p>Please see the Firebase JSON below used to send the notification to the Firebase news app. Anyone's help is highly appreciated. </p>
  
  <p>In the header I set authorization <code>key=firebase_server_key</code>
  and content type is set to <code>application/json</code></p>
  
  <pre><code>{
      "to" : "token received from firebase",
      "notification" : {
        "body" : "test",
        "title" : "Alert",
        "icon" : "myicon",
        "delivery_receipt_requested": true
      }
    }
  </code></pre>
  
  <p>Output from postman:</p>
  
  <pre><code>{"multicast_id":7845213569874521,"success":1,"failure":0,"canonical_ids":0,"results":[{"message_id":"0:4853214789631%31bd1c9631bd1c96"}]}
  </code></pre>