[Mimedefang] Previous relay information

[Whit Blauvelt]

On Wed, Dec 13, 2006 at 06:43:37PM +0900, Mark van Proctor wrote:

> Has anyone implemented some form of parsing of the received headers to
> determine who the previous relay was? When is the earliest time that these
> headers are available? filter_begin? Are these easily accessible through
> mimedefang's variables or will we need to build some kind of script that
> will parse the actual mail files?

Here's a way to get ahold of the Received headers. I haven't figured out the
earliest place it can go in the script. It certainly works if put just above
the call to SpamAssassin. 

    $HDRS = $CWD . "/HEADERS";
    open (HDRS) or md_syslog('warning', 'Cannot open the ' .  $CWD . ' HEADERS file!');
    @header = <HDRS>;
    close(HDRS);
    $headcount = @header;
    $n = 0;
    $r = 0;
    while ($n < $headcount) {
       if ($header[$n] =~ /Received:/) { 
          $received[$r] = $header[$n];   
          $r++;
       }
       $n++;
    }

Then here's how I'm getting rid of spam with a faked first Received "by
transpect.com" - since transpect.com isn't even the MX for transpect.com.

    $reccount = @received;
    $reccount--;
    if ($received[$reccount] =~ /by transpect\.com/) {
        md_syslog('warning','$MsgID: bytrans: ' . $received[$reccount]);
        action_discard();
    }

The previous relay you were after would be in $received[1] with this script.

Whit