[Mimedefang] md_check_against_smtp_server and md_graphdefang_log

[kd6lvw at yahoo.com]

--- On Mon, 3/25/13, James Curtis <jameswcurtis at hotmail.com> wrote:
> I did read through the mimedefang.pl file enough to find: ...
> AND this
> ($retval, $code, $dsn, $text) = get_smtp_return_code($sock, $recip, $server);
>  if ($retval ne 'CONTINUE') {
>  $sock->print("QUIT\r\n");
>  $sock->flush();  # Swallow return value
>  get_smtp_return_code($sock, $recip, $server);
>  $sock->close();
>  return ($retval, $text, $code, $dsn);
>  }

Poor coding (for today; perhaps OK in 2004).

Although this will issue a QUIT when an error is returned, it does NOT do so when the transaction succeeds to the point where 'DATA' is normally issued.  There are at least two blacklisting DNSBLs that track systems that track callbacks and the failure to issue QUIT.  This is a good way to get listed and therefore banned.