public function convertMessageToAltBody($message)
    {
        $message = preg_replace('/<head>(.*?)<\/head>/s', '', $message);
        $tags = ['</p>', '<br />', '<br>', '<hr />', '<hr>', '</h1>', '</h2>', '</h3>', '</h4>', '</h5>', '</h6>'];
        return trim(strip_tags(str_replace($tags, PHP_EOL, $message)));
    }