[Today’s post comes to us courtesy of Ping Xu]
Replacing a network adapter on the Essential Business Server 2008 Security Server may cause inbound and outbound email to queue and not be delivered. Confirm this by checking the message queue on the Security Server:
Reconfigure Internal and External DNS Lookups settings by using the Exchange Management Console.
Reconfigure Internal DNS Lookups setting:
Reconfigure External DNS Lookups setting: