    public function generateMessageFileName()
    {
        $time = microtime(true);

        return date('Ymd-His-', $time) . sprintf('%04d', (int) (($time - (int) $time) * 10000)) . '-' . sprintf('%04d', mt_rand(0, 10000)) . '.eml';
    }
The software uses insufficiently random numbers or values in a security context that depends on unpredictable numbers.