Thank you Per Hedeland, your solution worked.

Thanks
Dave

Per Hedeland wrote:
> In article <1159289092.729482.227350@m7g2000cwm.googlegroups. com>
> "davekaas@aol.com" <davekaas@aol.com> writes:
> >I am trying to change our DMZ to be more straightforward in how it
> >sends email. I have created a DMZ email hub that will forward email to
> >an internal system. I am using sendmail 8.17.7 and mailertables. When
> >I send a message to a user that exists on the internal network I get a
> >"User unknown" error on the external email hub.
>
> So (assuming you're sending to user@junk.com per your mailertable
> entries), this means that sendmail on the external hub considers
> 'junk.com' to be a local domain. You can verify this by noting that it
> is listed in the output of
>
> echo '$=w' | sendmail -bt
>
> This could be due to either your listing it in
> /etc/mail/local-host-names - in which case you should take it out from
> there - or due to sendmail finding that name by reverse-lookup of one of
> the locally configured IP addresses - in which case this should
> (from cf/README):
>
> confDONT_PROBE_INTERFACES DontProbeInterfaces
> [False] If set, sendmail will _not_
> insert the names and addresses of any
> local interfaces into class {w}
> (list of known "equivalent" addresses).
> If you set this, you must also include
> some support for these addresses (e.g.,
> in a mailertable entry) -- otherwise,
> mail to addresses in this list will
> bounce with a configuration error.
> If set to "loopback" (without
> quotes), sendmail will skip
> loopback interfaces (e.g., "lo0").
>
>
> >FEATURE(`mailertable',`dbm -o -T<TMPF> /etc/mail/mailertable')dnl
> >FEATURE(`access_db', `dbm -o -T<TMPF> /etc/mail/access')dnl
>
> Drop those '-o' options, they will mask any problems with the maps (not
> the cause of your problem though),
>
> --Per Hedeland
> per@hedeland.org