I m in process to transitioning my messaging environment from 2003 to 2007.
i am done with CAS and already removed 2003 owa from my exchange environment. Yesterday i have installed Hub transport role on my CAS server so that i can create file share witness.
As smart host we have Cisco ironport and all email going/coming thru that. i have added my Hub transport server IP in Ironport and here problem start coming. My clients started reporting that they are getting undelivered messages and those messages contains hostname of my Hub transport saying that '5.7.1 Client was not authenticated.
Mailboxes still running on 2003 and i did not make even a single change on Hub transport apart of installation..
Please help me..