I am migrating from Exchange 2003 to 2010, I would like to setup co-existance and followed the instructions for setup on technet. OWA redirects without issue, the problem I have is with RPC/HTTPS. Exchange 2003 mailboxes and connect directly to the Exchange 2003 server using RPC/HTTPS and Exchange 2010 mailboxes can connect through the Exchange 2010 CAS with RPC/HTTPS. The problem is if I try to use the 2010 CAS to proxy the RPC/HTTPS connections to Exchange 2003, Outlook never connects.
My UCC cert is valid and contains the external name as well as the legacy.domain.com I have tried switch IIS security to basic as was suggested on the technet forums
If anyone has any ideas I could try please let me know. Or even if they could point me to the right log files to see where the connection is failing on the CAS.