public function updateNotificationRecipients(&$list, &$comment)
    {
        //default is notification is on regardless of spam status
        $list = $this->owner->Authors();

        // If comment is spam and notification are set to not send on spam clear the recipient list
        if (Config::inst()->get(__CLASS__, 'notification_on_spam') == false && $comment->IsSpam) {
            $list = [];
        }
    }