Mailed database backups have mal-formed attachments

Wnen emailed database backups generated by dba automatic backups arrive, the attachment has a null file name associated with it. The following code change seems to fix it. The main change is the addition of the "Content Disposition" line.

function build_message($part) {
$message = $part["message"];
$message = chunk_split(base64_encode($message));
$encoding = "base64";
$pre = "Content-Type: ".$part["ctype"].($part["name"]? "; name = \"".$part["name"]."\"" : "");
if ($part["name"]) $pre .= "\nContent-Disposition: attachment; filename=\"".$part["name"]."\"";
return $pre."\nContent-Transfer-Encoding: $encoding\n\n$message\n";
}