We have installed a second domain (it is not a child domain) and have installed Exchange 2007 in a server of this second domain (call it seconddomain). I am able to send emails out to the internet but not to addresses that reside in the Exchange server from my first domain. I see that the meesages get stuck in the queue with error: 451 4.4.0 primary target IP address responded with "4184.108.40.206 unable to connect."attempted failover to alternate host, but that did not succeed.Either there are no alternate hosts, or delivery failed to all alternate hosts.
If I click retry again, I then get error: 451 4.4.0 Primary target IP address responded with:"454 4.7.0 Temporary authentication failure"
I ran the Exchange Troubleshooter and get the followint error: Computer account for 'SMTPSVC\Exchangeserver.seconddomain' not found in Active Directory. No computer account in Active Directory has 'ServicePrincipalName' set to 'SMTPSVC/Exchangeserver.seconddomain' . This will result in Kerberos authentication failures when server Exchange server attempts to create an SMTP connection to another Hub Transport server. Any tips or suggestions? Thanks in advance!