Configure sendmail to reject mail for unknown users?

[Les Mikesell]

On Mon, 2006-03-13 at 18:10, Timothy Alberts wrote:
> > 
> > It should always reject email to invalid users.  Is this a
> > separate machine configured as an internet relay that
> > doesn't have the actual accounts?  If so, you might set
> > up the valid users in the virtusers table with explict
> > forwarding if there aren't too many instead of blindly
> > forwarding for the domain.   A nicer approach is to install
> > MimeDefang which has an option to check recipients via smtp
> > on the final destination host before accepting on the relay.
> > And it can do whatever virus and spam checks you might want, too:
> > http://www.mimedefang.org/
> > 
> 
> There's only one server, there's only one domain, it has all the
> accounts on it and no I'm not using the virtusers (should I be?).

If the server isn't set up to relay to a hub machine or
forward via mailertable, then it should automatically
reject any address that is not a local account.  Maybe
you have PostmasterCopy enabled.  Look in sendmail.cf
to be sure that 
#O PostmasterCopy=Postmaster
has the leading # to comment it out.  I've forgotten the
sendmail.mc invocation that would enable it but these
days you probably don't want it on.

Virtusers is mostly useful if you forward or accept for more
than one domain or wish to appear to.

-- 
  Les Mikesell
   lesmikesell at gmail.com