/**
  * Check to see that the email address provided
  * is on the white list.
  *
  * @param $event
  * @return mixed
  */
 public function onUniqueEMailValidator($event)
 {
     $canRegister = \humhub\models\Setting::Get('anonymousRegistration', 'authentication_internal');
     $registerModel = new \humhub\modules\user\models\forms\AccountRegister();
     if ($canRegister) {
         if ($registerModel->load(Yii::$app->request->post())) {
             if (!EmailWhitelist::emailIsAllowed($registerModel->email)) {
                 $event->isValid = false;
                 return Yii::$app->getResponse()->redirect(Url::to(['/email_whitelist/denied/index']));
             }
         }
     }
 }