code: def send_notification(self, user, sender=None, **kwargs):
          
          if not user.is_active:
              return False
          self.email_message(
              user, self.notification_subject, self.notification_body, sender, **kwargs
          ).send()
          return True
docs: An intermediary function for sending an notification email informing
          a pre-existing, active user that they have been added to a new
          organization.