Microsoft Exchange couldn’t establish an encrypted Kerberos LDAP connection to %1. Please ensure that the domain controller %1 is running Windows 2000 Server SP3 or later. %4

This Error event indicates that the Exchange server could not establish an encrypted Kerberos Lightweight Directory Access Protocol (LDAP) connection to the domain controller specified in the event description because the domain controller was not running the required version of Microsoft Exchange Server.

To resolve this error, do one or more of the following:

• Review the System and Application event logs for related events. For example, events that occur immediately before and after this event may provide more information about the root cause of this error.

• Run the tools that Exchange offers to help administrators analyze and troubleshoot their Exchange environment. Open the Toolbox node of the Exchange Management Console to run these tools.

If you cannot resolve this error, or you experience other problems or mail flow interruptions in your Exchange environment after attempting to resolve this error, contact Microsoft Product Support. For information about contacting support, visit the Microsoft Help and Support Web site.

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.