public function actions()
 {
     return array_merge(parent::actions(), ['export' => ['class' => ExportAction::className(), 'dataProvider' => function ($params) {
         $searchModel = new MailSearch();
         $dataProvider = $searchModel->search($params);
         return $dataProvider;
     }]]);
 }
 public function behaviors()
 {
     return ArrayHelper::merge(parent::behaviors(), ['verbs' => ['class' => VerbFilter::className(), 'actions' => ['delete' => ['post']]]]);
 }