Hi, I need some help about coexistence of Exchange 201 and Exchange 2013.
I have an environment with 2 Exchange Server 2010 (One HUB/CAS another MBX/HUB/CAS and Forefront for Exchange 2010) and now I have configured an Exchange Server 2013 (MBX and CAS).
For now, I have moved 3 mailboxes from Exchange 2010 to Exchange 2013 but the mailboxes cannot receive or send emails, the emails are stuck on Exchange 2010 Queue (Hub 15) with the message:
" 451 4.4.0 Primary target IP address responded with:"421 4.4.2 Connection dropped due to SocketError." Attempted failover to alternat host, but did not succeed. Either there are no alternate hosts, or delivery failed to all alternate host.
I can telnet from Exchange 2013 to Exchange 2010.
I have enabled the Verbose log on Exchange 2010 Receive Connectors from both servers but in the logs there is no entry from Exchange 2013 IP.
If anyone can help me I appreciate.
Best Regards.