// 下記プロパティを追加
	var $language;
	var $encoding;

// 下記メソッドを上書き
	function __mail() {
		if (!empty($this->language)) {
			$language = mb_language(); 
			mb_language($this->language);
		}
		if (!empty($this->encoding)) {
			$encoding = mb_internal_encoding();
			mb_internal_encoding($this->encoding);
		}
		if (ini_get('safe_mode')) {
			$result = @mb_send_mail($this->to, $this->subject, $this->__message, $this->__header);
		} else {
		$result = @mb_send_mail($this->to, $this->subject, $this->__message, $this->__header, $this->additionalParams);
		}
	
		if (!empty($language)) {
			mb_language($language);
		}
		if (!empty($encoding)) {
			mb_internal_encoding($encoding);
		}
		return $result;
	}