/**
* Evaluates the message and returns modifications for inline images and backgrounds
*
* @access private
* @param string $message
* @param string $basedir
* @return string $message
* */
private function MsgHTML($message, $basedir = MODX_BASE_PATH) {
    preg_match_all("/(src)=\"(.*)\"/Ui", $message, $images);
    if(isset($images[2])) {
        foreach($images[2] as $i => $url) {
            // do not change urls for absolute images (thanks to corvuscorax)
            if (!preg_match('/^[A-z][A-z]*:\/\//',$url)) {
                $filename = basename($url);
                $directory = dirname($url);
                ($directory == '.')?$directory='':'';
                $cid = 'cid:' . md5($filename);
                $fileParts = preg_split("/\./", $filename);
                $ext = $fileParts[1];
                $mimeType = $this->modx->mail->mailer->_mime_types($ext);
                if ( strlen($basedir) > 1 && substr($basedir,-1) != '/') { $basedir .= '/'; }
                if ( strlen($directory) > 1 && substr($directory,-1) != '/') { $directory .= '/'; }
                if ( $this->modx->mail->mailer->AddEmbeddedImage($basedir.$directory.$filename, md5($filename), $filename, 'base64',$mimeType) ) {
                $message = preg_replace("/".$images[1][$i]."=\"".preg_quote($url, '/')."\"/Ui", $images[1][$i]."=\"".$cid."\"", $message);
                }
            }
        }
    }
    return $message;
}