This event indicates that the Exchange server may be unable to contact a domain controller. Alternatively, the Exchange server time may be out of sync with the domain controller time.

To resolve the error, follow these steps:

• Make sure that the Exchange server has network connectivity with the domain controller.
  
  
• Synchronize the Exchange server time with either the domain controller time or the time server that is used by the domain controller.
  
  
• Try to start the Microsoft Exchange System Attendant.
  
  
• Resolve your issue by using self-support options, assisted support options, and other resources. You can access these resources from the Exchange Server Solutions Center. From this page, click Self-Support Options in the navigation pane to use self-help options. Self-help options include searching the Microsoft Knowledge Base, posting a question at the Exchange Server forums, and others. Alternatively, in the navigation pane, you can click Assisted Support Options to contact a Microsoft support professional. Because your organization may have a specific procedure for directly contacting Microsoft Technical Support, be sure to review your organization's guidelines first.
  
  

If you are not already doing so, consider running the Exchange tools created to help you analyze and troubleshoot your Exchange environment. These tools can help make sure that your configuration aligns with Microsoft best practices. They can also help you identify and resolve performance issues, improve mail flow, and better manage disaster recovery scenarios. To run these tools, go to the Toolbox node of the Exchange Management Console. To learn more about these tools, see Managing Tools in the Toolbox.