I just upgraded from GW6 to GW8 a few weeks ago. Since then, we seem to have some trouble with sending and receiving mail to external GW domains. Before the upgrade, everything worked fine. Now, whenever I try to send am email to a person at the external domain, the message properties says "pending" and never goes anywhere. All the domains show as "Open" on both on my MTAs. I have no problems with Internet mail going to domains not configured in my system.

I've attached a diagram of my configuration.

I have a primary domain on an internal network. There is an MTA and a few POAs on this domain. The MTA and one POA are both running on one server. This server is not directly reachable from the Internet. A secondary domain is in a DMZ and in that domain is an MTA, GWIA and Webaccess all on the same server. There is a NAT translation on the firewall and this server has a public IP address.

Now, here's the part I'm concerned about. In my link configuration, I have the primary domain configured with "direct" links to the external domains via TCP/IP. The Second domain is configured with "indirect" links to external domains via a "direct" link to the primary domain. This does not seem intuitive to me.

I tried reconfiguring a couple of these links by setting the primary domain to have an "indirect" link to an external domain via the link to the secondary domain. And I set the secondary domain to have a "direct" link to the same external domain via TCP/IP. However, when I did this, the external domain showed as closed on the secondary domain's MTA.

So what would be the recommended way to configure links to external domains using a secondary domain in a DMZ?