Exchange 2003 and 2010 coexisting - messaging loop

[hkxuser]

Hi all. I have had an Exchange 2003 SP2 box on my network for several years, and recently introduced a 2010 Exchange server. Right now I have them both up and running, and have moved 3 users to the new Exchange server. This worked just fine for a week and a half, but now I have a rather annoying problem. The three users on the new Exchange server cannot receive email from the internet, or from the users on the Exchange 2003 box. They can only receive messages from the other two users on the new Exchange box. The Exchange 2003 users are just fine, and can receive internet mail and internal mail from everybody except the Exchange 2010 users.

The Exchange 2003 box is still functioning as a back end server. Internet mail is still routed to the Exchange 2003 box. This is a simple environment. I have only one SMTP virtual server on the Exchange 2003 box. There is no smart host. Anyway, messages sent to the Exchange 2010 users are bouncing back with NDR's (5.3.5 errors). There are logs in the Event viewer on the Exchange 2003 server indicating that there is a looping condition, and that the server is configured to route mail back to itself. I get this message in the Event viewer any time a piece of mail is sent to an Exchange 2010 user. I don't see any messages on the Exchange 2010 box that mention a looping condition.

In googling around people suggest to remove the routing group connector that was installed by default when I set up the Exchange 2010 box, and then set it up again. I have done that, with no results. The same problem occurs. Does anybody here have any suggestions? I am at my wit's end on this one. Thanks in advance for any help.

 

[58sniper]

Check these things...

Organization Configuration>Hub Transport>Accepted Domains.
Are the domains listed "authoritative"?

Organization Configuration>Hub Transport>Send Connectors.
Open each, click on the Source Server tab, and make sure only the 2010 box is listed. Then click on the Network tab and make sure just the top option is selected.



Pat Richard MVP
Plan for performance, and capacity takes care of itself. Plan for capacity, and suffer poor performance.

http://www.ucblogs.net/blogs/exchange/

 

[hkxuser]

I thought I had replied to this already, but it is not showing in the forum, so here goes again...

First off, thanks very much sniper for your response and attention to this.

- I checked the accepted domains. My domain is there and listed as authoritative. The weird thing is, I have two other domains listed there (both are not listed as authoritative). One is the private IP of the Exchange 2003 server, the other is the old public IP that was NAT'ed to the Exchange 2003 server. It is no longer used as we switched ISP's a couple of months ago. I have no idea why they are there. They appeared there after I did the Exchange 2010 install. If I try to delete them it errors out, telling me that they are referenced in an email address policy. When I go to the email address policy and try to remove them there, it runs through the wizard but then errors out at the end and so I have been unable to get rid of them so far.

- I checked the send connector (there is only one there and it was created by default during the install). There is not a source sever listed. When I try to add the Exch2010 box it gives me an error saying "the source server EXCH2010 isn't in the connector's source routing group". I had noticed this a few days ago and created a new send connector. In that send connector I was able to add the EXCH2010 box without a problem, and mail still flowed for a couple of days. I deleted that send connector yesterday while trying to troubleshoot my problem. Obviously that didn't work. I did check the Network tab and the top option is the only one selected. Any ideas what's going on?