[Mimedefang] Easy way to tell message is sent from local machine?

[David F. Skoll]

On Fri, 7 Jun 2002, Nate Carlson wrote:

> One problem is that I have a ton of dialup users authenticating via
> sendmail and then sending out.. I can't add all their IP's (I have no idea
> where they will be coming from), but is there a way in MimeDefang to tell
> if the user has authenticated to Sendmail? Not even sure is Sendmail
> passes this info, but hey, it's worth a shot.  :)

There is a way for Sendmail to pass macros to milter (which will let
you tell if a user is authenticated or not), but currently, MIMEDefang
doesn't give access to those macros.  It's on my TODO list.

Some workarounds:

Do the dial-up users dial directly into the Sendmail machine?  If not,
why not just NAT them to a single IP address when they access the mail
relay?  You could have firewall rules that only NAT connections from
dialup users to TCP port 25 to your mail server to minimize
disruption.

Can you set up a separate Sendmail box for dial-up users to use as
their outgoing relay and then have it use the real box as a smarthost?
Again, this will make all internal mail come from a single IP address.

Regards,

David.