public function getEMailParam($name, $default = null, $optional = false)
    {
        $value = $this->getParam($name, $default, $optional);
        if ($value !== null) {
            if (!preg_match('/^.+@.+\...+$/', $value)) {
                throw new InvalidParameterException("Parameter '{$name}' is invalid");
            }
        }
        return $value;
    }