Final stretch to our cross-domain configuration...except

We are doing some tests on a cross-domain configuration. Everything is in place. Configuration documents (inbound-Outbound) are in place in the admin4. It's working for the majority of our domain (8 out of 10).
For one domain, they cannot rename a user to their own domain.

Here's the complete (long) description

Link

Any ideas?

JYR

One stop shop for troubleshooting Domino and DNS

Problem

Unable to route outbound smtp mail relating to Domino and DNS.

Symptom

- Messages back up in the mail.box.
- The router task displays the error message 'Waiting for DNS availability'.
- The server attempts to connect to an internet domain rather than the mail exchanger.

a few solutions...
Technote 1420956
Link