Email Validation In Yii Model

From my sourcecode, I gave the information for email validation in yii framework.

<?php
class User extends CActiveRecord
{
  public static function model($className=__CLASS__)
  {
      return parent::model($className);
  }
  public function tableName()
  {
      return 'tbl_user';
  }
  public function rules()
  {
          array('email','email'),
          array('email','unique'), //option
  }
}
?>