That would tend to indicate that the mail is being routed through the Exchange 2003 server and you don't have a properly scoped send-connector on the 2010 side.
Regards, Michael B. Smith Consultant and Exchange MVP http://TheEssentialExchange.com From: Paul Steele [mailto:paul.ste...@acadiau.ca] Sent: Monday, May 03, 2010 12:47 PM To: MS-Exchange Admin Issues Subject: RE: Exchange 2003 to 2010 issues Yes, I had already done that. I'm a bit confused now though. I stopped/started the SMTP virtual host (on the EXCH2003 side), and that seemed to solve the problem. Things seem to be working so I guess whatever was broken/stuck is ok. At least it's working... From: Michael B. Smith [mailto:mich...@smithcons.com] Sent: May-03-10 12:40 PM To: MS-Exchange Admin Issues Subject: RE: Exchange 2003 to 2010 issues Did you create a send-connector to forward the scoped domain to the Unix host? Regards, Michael B. Smith Consultant and Exchange MVP http://TheEssentialExchange.com From: Paul Steele [mailto:paul.ste...@acadiau.ca] Sent: Monday, May 03, 2010 11:37 AM To: MS-Exchange Admin Issues Subject: Exchange 2003 to 2010 issues We did as much testing as we could in our test lab, so we moved ahead and installed our production Exchange 2010 server. The installation went fine without any errors, but we're have delivery problems. We've been preparing for a transition from Exchange 2003 to Exchange 2010. We've done various test installs in our lab and thought we had everything figured out. Unfortunately we're having mail delivery problems after completing the install. The actual installation went without problems. We have a shared address space, with some users on our Exchange server and some on a Unix host. The biggest issue we're having is sending to users who are not on our Exchange server. We've set the Accepted Domains for "acadiau.ca" to Internal Relay, but when we try to send to usern...@acadiau.ca<mailto:usern...@acadiau.ca> that does not exist in the Exchange name space, the message bounces (it never makes it to our Unix smart host). We've compared things with our test servers and everything looks correct. At this point we've very confused what we're doing wrong. If anyone has a suggestion what to look for we really appreciate it.