Функция проверки валидности email

function validEmail($email = '') {
    $result = false;
    $email = filter_var($email, FILTER_VALIDATE_EMAIL);
    if ($email) {
        $arr = explode("@",$email);
        $result =  getmxrr($arr[1], $a);   
    }
    return $result;
}
var_dump(validEmail('mail@gcom.com'));