We have recently migrated from exchange 2003 to exchange 2007 we had a few bumps in the road but for the most part it was smooth.The environment isall 2003 server sp2 and exchange 2007 sp1. The environment is set up on 1 hub server (Hub.mydomain.com),1 client server (client.mydomain.com)and 1 SCC cluster (Exch2007.mydomain.com)for the mailbox and public folder store.The issue is this we have an application Metaviewer that sends documents electronically via e-mail. The email configuration is very basic you select the protocol (SMTP) the from email address, theFQDN of the SMTP server, and credentials of a domain account.What Ithought was going to be a simple matter of creating a connector inthe hub server configuration has not worked as expected.The connector is set up to receive IPV4 addresses from the IP of the metaviewer PC port 25, the authentication is integrated windows, and permission group is anonymous users.What is strange is that when we select the Hub server as the SMTP server hub.mydomain.com and enter credentials the software will come back and say that this is not an SMTP server (occasionally)Other times the email works and sends it through with no problem. So the issue happens very intermittently at one time when it was hot working grasping at straws I entered the mailbox store Exch2007.mydomain.com and tested and it worked e-mail was being sent (occasionally) then it stopped working. I changed it back to hub.mydomain.com and it worked again for a little while and then stopped. My understanding is the Hub is the SMTP server and that all e-mail to and from the environment needs to go through the hub role, I turned on connection logging and I am not seeing any errors there or in the system event logs. When I point the SMTP server back to the old 2003 exchange the emails are sent consistently without a problem. Any help that can be provided will be appreciated this is the last step in the migration process before I can turn off the old server to test the environment prior to decommission the old server.

Did you try creating new Receive connector for the application as per below guide? Allowing application servers to relay off Exchange Server 2007 http://msexchangeteam.com/archive/2006/12/28/432013.aspxAmit Tank | MVP Exchange Server | MCITP: EMA | MCSA: M | http://ExchangeShare.WordPress.com

Hi Schuml, I would like to know whether the application Metaviewer is authenticated by the Exchange Hub Server to send message or send message by using the anonymous account. In addition, I suggest you enable SMTP log on the Receive Connector which used to receive message from application Metaviewer to troubleshoot the issue. How to Configure Protocol Logging http://technet.microsoft.com/en-us/library/bb124531.aspx If any error when the application Metaviewer attempts to telnet to Hub Server to submit message, please post result here. In addition, I suggest you double check whether the application Metaviewer is able to resolve Hub.mydomain.com to correct IP address. I suggest you add a host entry for Hub.mydomain.com to test the issue. Mike Shen TechNet Subscriber Support in forum If you have any feedback on our support, please contact tngfb@microsoft.com

Hi,You should only point to HUB server for relaying for any application not mailbox server as this is for MAPI connectivity only.As Mike suggestyou shouldenable SMTP log on the Receive Connector which used to receive message from application Metaviewer to troubleshoot the issue.If you are using any service account for credential in Metaviewer then no need to allow anonymous access on receive connector.Also check with IP of HUB server instead of host name Hub.mydomain.com and then check.Anil

Thank you all for your replies the combination of all of them helped me resolve the issue. I enabled logging on the metaviewer connector using this article http://technet.microsoft.com/en-us/library/bb124531.aspx, I saw that there was an error 550 5.7.1 Unable to relay. So using the article http://msexchangeteam.com/archive/2006/12/28/432013.aspxI added the metaviewer to the Exchange servers security group and then modified the connector: Authentication (TLS) andExternally Secured, thepermission group is Exchange Servers. I did several tests this morning and everything was successful. I am not sure why it was working intermittently with the other settings.