[Mimedefang] DNS and MX records

[Les Mikesell]

On Mon, 2006-05-15 at 07:43, netguy wrote:
> >> It was described in a now-expired ietf document 
> >> draft-delany-nullmx-00.txt,
> >> still available at:
> >> http://ietfreport.isoc.org/all-ids/draft-delany-nullmx-00.txt
> >
> >
> 
> This does not answer the question of how to stop spammers from using 
> network resources.  So that is probably very wishfull thinking but if 
> another avenue could be taken away from them...  Spam is sent to 
> domain.tld WITHOUT checking MX records.

If you don't include the domain in local-host-names sendmail
should reject everything at the RCPT TO step before DATA
is permitted.  That still consumes some resources but should
be insignificant compared to the ones you accept and scan.

-- 
  Les Mikesell
   les at futuresource.com