We have an environment which primarily comprised of Exchange 2007 Servers. There are 2 nodes of ccr cluster, 2 Hub/Cas servers and 2 Edge servers. We want to migrate this entire setup to Exchange 2010. Firstly we upgraded all these servers to Exchange 2007 SP2 and we also upgraded the CCR Cluster instance. We ran the Exchange pre deployment assistant and confirmed that our environment was ready to accept Exchange 2010. Once we confirmed that all was well we un installed the second Hub/Cas server gracefully and formatted that machine and installed Windows 2008 R2 and Exchange 2010 Hub/Cas server. We added Microsoft Exchange Subsystem group to all the Exchange Servers in the organization. Next we installed on a new hardware with large storage, Exchange 2010 Mailbox Server. Once we installed this server, we created a few dummy mailboxes for test purpose. We sent test messages from the mailboxes located in the Exchange 2010 database and found that mailflow was working fine in between these mailboxes, but we are unable to replay messages in between Exchange 2007 and Exchange 2010 Hub/Cas Servers. Is there any particular way we have to configure the connectors in order to achieve this or is it very straight forward. Please enlighten and assist. With Regards, M.R.Pai

What happens to the messages? Are they queued on the hub transports? Have you run ExBpa against the org or the message flow troubleshooter in the EMC toolbox? Any errors in the event logs?

I would highly suggest using the mail flow troubleshooter, tracking log explorer and routing log viewer to have am indepth idea about the flow of these emails.

Are they all in the same AD Site? The mail flow should work nicely with no additional configuration. So, the problem you encouter must have something to do with AD Site or DNS settings. Please explain in detail your AD Site configuration and IP subnets.... Regards, -ferry-

Do you have both 2007 HUB and 2010 HUB in your environment? If not, you need BOTH during co-existence. 2010 HUB server won't handle email flow from or to a 2007 mailbox. Check http://www.howexchangeworks.com/2010/07/there-is-no-available-hub-transport.htmlRajith Enchiparambil | http://www.howexchangeworks.com |

Hi, Which queue did the message stuck? Any error message appear in the queue? Any NDR was received from the sender? As others said, you can run the Mail Flow Troubleshooter in the EMC to do the basic check. Thanks Allen

Hi All, Thank you so much for all your inputs. However, we did not decide to keep things pending and moved all the mailboxes to Exchange 2010. Now we have a proper and a working mail system. Thank you all once again.M.R.Pai

HI Pai, Did you have both 2010 and 2007 HUB when you had the issue?Rajith Enchiparambil | http://www.howexchangeworks.com |