Configure sendmail to reject mail for unknown users?

[Les Mikesell]

On Mon, 2006-03-13 at 17:11, Timothy Alberts wrote:
> On Mon, 2006-03-13 at 17:03 -0600, Mike Klinke wrote:
> > I use the access file mechanism:
> > 
> > =================================== 
> > #to reject mail addressed to old or bogus accounts
> > 
> >     exDomain.com             REJECT
> > 
> > #below statements will override above REJECT statement
> > 
> >     validUser1 at exDomain.com      OK
> >     validUser2 at exDomain.com      OK
> > ====================================
> > 
> > Regards, Mike Klinke
> 
> That easy eh?
> 
> All this time I've been doing the access method, but apparently
> backwards.  I've been listing all the invalid accounts that get used
> (when I find them) and adding them as rejects.
> 
> Now if a mail comes in that is 'TO/CC/BCC:validuser at mydomain.com' and
> 'TO/CC/BCC:invaliduser at mydomain.com' will it reject the entire mail, or
> will it still deliver to the valid user?

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/

-- 
  Les Mikesell
   lesmikesell at gmail.com