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