function mimemail_extract_files($html) {
  $pattern = '/(<link[^>]+href="?|<object[^>]+codebase="?|@import |src="?)\/?([^"]+)("?)/emis';
  $html = preg_replace($pattern,'"\\1". _mimemail_file("\\2") ."\\3"', $html);
  
  $document = array(array(
    'Content-Type' => "text/html; charset=utf-8",
    'Content-Transfer-Encoding' => 'base64',
    'content' => chunk_split(base64_encode($html)),
  ));
  
  $files = _mimemail_file();
  
  return array_merge($document, $files);
}