From: zhipeng on

we're about to run two Exchange 2007 servers in two sites within the
same Domain. I've setup both the Exchange Servers and configured the
Receive and Send connectors.

The Receive Connectors on both the Exchange servers have 'Exchange
Servers' checked under the Authentication Tab and also 'Exchange
servers' are checked on the Permission Group Tab.

Nevertheless, when I send an email as a user on ServerA to a user on
ServerB the mail gets stuck in the Queue with error message:

451.4.4.0 primary target IP address responded with:" 451 5.7.3. Cannot
achieve Exchange Server Authentication."Attempted failover to alternate
host,but that did not

succeed.Either there are no alternate hosts,or delivery failed to all
alternate hosts.

any idea?


Thank you