code: def read(self, request, pk=None):
          
          from .settings import stored_messages_settings
          backend = stored_messages_settings.STORAGE_BACKEND()
  
          try:
              backend.inbox_delete(request.user, pk)
          except MessageDoesNotExist as e:
              return Response(e.message, status='404')
  
          return Response({'status': 'message marked as read'})
docs: Mark the message as read (i.e. delete from inbox)