[Mimedefang] Comparing relay IP and dns name

[Mark Wiater]

Hi All,

I added some code in filter_relay to see if some form of the relay's ip
address appears in the dns name. It's common for ISP's to create reverse
dns addresses that contain DHCP-issued address.

I'm currently only logging those to syslog but I wanted to ask you all
what you think of the validity of at least tempfailing a connection from
such a relay?

Thanks

Mark


----- from filter_relay ----------

if($name =~ /$ip/ && $name !~ /^\[/){
   md_syslog('warning', "filter_relay: $name contains $ip ");
   $relayIsDHCP=1;
}