code: def process_message(message, notification):
      
      # Confirm that there are 'notificationType' and 'mail' fields in our
      # message
      if not set(VITAL_MESSAGE_FIELDS) <= set(message):
          # At this point we're sure that it's Amazon sending the message
          # If we don't return a 200 status code, Amazon will attempt to send us
          # this same message a few seconds later.
          logger.info('JSON Message Missing Vital Fields')
          return HttpResponse('Missing Vital Fields')
  
      if message['notificationType'] == 'Complaint':
          return process_complaint(message, notification)
      if message['notificationType'] == 'Bounce':
          return process_bounce(message, notification)
      if message['notificationType'] == 'Delivery':
          return process_delivery(message, notification)
      else:
          return HttpResponse('Unknown Notification Type')
docs: Function to process a JSON message delivered from Amazon