public function send(Message $message)
{
// get message with generated html instead of set FileTemplate etc
$ref = new \ReflectionMethod('Nette\\Mail\\Message', 'build');
$ref->setAccessible(TRUE);
/** @var Message $builtMail */
$builtMessage = $ref->invoke($message);
$time = date('YmdHis');
$hash = substr(md5($builtMessage->getHeader('Message-ID')), 0, 6);
$path = "{$this->tempDir}/{$time}-{$hash}.mail";
FileSystem::write($path, serialize($builtMessage));
$this->files = NULL;
}