We, National Institute of Public Health in Norway, run LISTSERV 1.8d on Win
NT with Exchange Server 5.5. LISTSERV and Exchange run on separate machines
and different domains. For our internal users the system works fine. Now
that we want to make our lists available for people outside the institute
we are having problems getting it to work as we want. If anyone else have
got a similar setup to work we will be happy to get in touch with you.

Here are some details about our system, and a short description of what is
working and what is not:

Our system is set up on two servers where "machine1" is running our
mailserver and "machine2" is running LISTSERV. There is a firewall between
the two servers and machine1 is inside the FW and machine2 is placed on the
DMZ-segment of the FW together with the web-server. Our primary domain is
folkehelsa.no and we have a subdomain for the lists, list.folkehelsa.no.

If an internal user, [log in to unmask], subscribes to a list he get all
the expected response from LISTSERV. After confirming his subscribtion to a
list he can send messages to it and operate it as defined.

When an external user with email address other than @folkehelsa.no send a
subscription request to a list the user is added to the list as he is
supposted to, but he never receive any confirmation form the list. This
user can now send messages to the list as any of the internal members and
the mail is distributed to all the internal members of the list as normal.
Still the external member doesn't receive any messages from the list.

From this we tend to conclude that the communication between LISTSERV and
Exchange works fine and that the reason for the problem is that there might
be something missing in our Exchange setup which allow mails that are sent
from other domains/machines to be forwarded to users. Does anyone have any
ideas on this?

We would be grateful for any help.

Tor-Arne Bertheussen,
National Institute of Public Health,
Oslo, Norway