Setting up a coexist environment between 2003/2010. Under Administrative Groups I have the Exchange 2010 Group.
"Exchange Administrative Group (FYDIBOHF23SPDLT)"
and the Exchange 2003 Group
"First Administrative Group"
In each group I see the connector that the first CAS server created.
2010
MTAEXCH-CAS01-EXCHANGE
2003
EXCHANGE-MTAEXCH-CAS01
I migrated a test user to the 2010 server and created a new mailbox for another test user on the 2010 server. I can send mail from both 2010 users to any 2003 user. I cannot send mail from the 2003 server to a 2010 user. Looking at Exchange 2003 ESM, I see in the queues the message goes into the “Exchange-MTAEXCH-CAS01 (Routing Group Connector)” then gets moved to the “Messages with an unreachable destination”. The system is not in production yet, just testing.
