protected static function load_config($config=null) {
	if ($config) {
		self::$config = $config;
		return;
	}
	
	$config_file = ROOT_DIR.'config/email.ini';
	if (file_exists($config_file) == false) {
		$exception = bootstrap::get_library('exception');
		throw new $exception('no email config found');
	}
	
	self::$config = parse_ini_file($config_file);
	
	// decode the password
	self::$config['pass'] = base64_decode(self::$config['pass']);
}