Thanks for the reply, Boris. Here are some more details to clarify the situation.
I.) The MX record for "mydomainA" is setup properly at easyDNS to use the easyDNS servers and email forwarding to Client-A's 15 ISP email boxes.
2.) "Mydomain" is hosted on an SME 6.0 server at another related site - call it Client-B.
3.) When external users (those not at the Client-B site) send email, eveything is fine.
4.) When Client-B users (from behind the SME server) try to send email to Client-A users, the mail bounces with "unknown user" since the SME server never looks "outside" its own managed domains for the MX record.
My question is how to "force" the SME server to go outside for this domain and thus deliver email from Client-B to Client-A. Again, I think I saw this solution here but now can no longer find it.
I know I can setup duplicate forwarding addresses at the SME server, and have done this in similar cases where I have only a couple of email addresses. But this is double maintenance and a source of problems if one of the addresses changes and both forwarding addresses are not updated.
I should have added these details in the first post but was trying to avoid a long post.
Thanks again for any and all replies.
jim