[Mimedefang] DNS and MX records

[Les Mikesell]

On Mon, 2006-05-15 at 09:43, John Rudd wrote:

> >> 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.
> 
> or, going with the topic of this list, if you wanted to accept mail for 
> postmaster and abuse, you could keep the domain in local-host-names, 
> but filter out any recipients for that domain (except postmaster and 
> abuse) during filter_recipient.

Or probably more efficiently, let sendmail do it by using
virtusertable with postmaster and abuse addresses forwarded
somewhere and the rest of the domain rejected with:
# catch-all error for unknown users
@domain.name error:nouser No such user here

That way it shouldn't even hit the perl code.
If you have other domains you want to handle the same way,
you can map them together like:
@other.domain1 %1%3 at domain.name
@other.domain2 %1%3 at domain.name

-- 
  Les Mikesell
   les at futuresource.com