To resolve this error, follow these steps:
Review MSExchangeADAccess Event 2150 for a list of domain controllers, global catalog servers and configuration domain controllers available in the Active Directory topology. Use the Ping or PathPing command-line tools to test basic connectivity to these Active Directory servers. Use Ping to isolate network hardware problems and incompatible configurations. Use PathPing to detect packet loss over multiple-hop trips. For more information, see Microsoft Knowledge Base article 325487, How to troubleshoot network connectivity problems.
Run the Dcdiag command line tool to test domain controller health. To do this, run dcdiag /s:<Domain Controller Name> at a command prompt on the server that is running Microsoft® Exchange Server. Use the output of Dcdiag to discover the root cause of any failures or warnings that it reports. For more information, see Dcdiag Overview.
Make sure that Exchange Enterprise Servers and Exchange Servers security groups are added to Manage Auditing and Security Log under Default Domain Controller Security Settings. To do this, follow these steps:
In the Default Domain Controller Security Settings snap-in, under Security Settings, expand Local Policies and select User Rights Assignment.
In the right pane, right-click Manage Auditing and Security Log and then click Properties.
Make sure that the Define these policy settings check box is selected and Exchange Enterprise Servers and Exchange Servers appear on the list underneath.
Review related Error and Warning events in the Application log. These related events may help you find the root cause of this error.
If you are not already doing so, consider running the tools that Microsoft Exchange offers to help administrators analyze and troubleshoot their Exchange environment. These tools can help you make sure that your configuration is in line with Microsoft best practices. They can also help you identify and resolve performance issues, improve mail flow, and better manage disaster recovery scenarios. Go to the Toolbox node of the Exchange Management Console to run these tools now. For more information about these tools, see Toolbox in the Exchange Server 2007 Help.