EventID: 8026
Windows Server 2003 SP2
Exchange Server 2003 Enterprise
https://support.microsoft.com/kb/272552?wa=wsignin1.0
This error commonly occurs after dcpromo has been run for a domain controller demotion event.
To clear the error, open up the Exchange System Manager, goto Recipient Update Service and update the Recipient Update Service (Enterprise Configuration) and Recipient Update Service ([Your Domain]) to reflect the FQDN of the new domain controller.
