We have installed a new exchange 2007 server in to our exchange forest. ( not really large, just our current box is a 2003) Everything went great. Connectors got setup. Mail can go back and forth! HOWEVER, When a user who is on the 2007 box sends a email to more then one user who is on the 2003 and the 2007 box, the emails will go to the people on the 2007 box. But none of them will go to the users on the 2003 box. If you send to a single person from 2007 to 2003 it works just fine, but trying to send to more then one user and none of the emails will route to the 2003 box. I have recreated the connectors many times. Reinstalled exchange 2007. inheritance is setup correctly. I'm pulling my hair out here! Please Help! -Dylan Brennan

Do they get an NDR? What does message tracking show?

Hi, Run Mail Flow Troubleshooter in Exchange Troubleshooting Assistant http://blogs.technet.com/b/exchange/archive/2006/08/07/3394688.aspx Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

Here are the following errors given from the Mail Flow Troubleshooter. This being the main error now. SMTP instance 'Default SMTP Virtual Server' on server cib01 failed the mail acceptance test over port 25. RCPT TO command: Respond = . Sender ID filtering is set to accept messages that fail the Sender ID validation test. Key 'LM/SmtpSvc/1/Domain/icclos.com' was found in the metabase on server cib01 but multiple corresponding GUIDs are found for this entry. Unless multiple recipient policies have same SMTP addresses, this could be the result of conflicting entries in recipient policies and SMTP connectors such as an SMTP connector addressed to an authoritative SMTP domain.

Hi, Does the domain in the Accepted Domain? Check E-mail Address Policies if the domain is writen in the Policy. Please remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.