Process %1: An exception occurred while attempting to locate a Client Access server to handle a request for e-mail address %2. The returned exception is %3.

This Error event indicates that a failure occurred while locating Microsoft Exchange Server that runs the Client Access server role that is required to retrieve Schedule+ Free Busy information for the e-mail address specified in the event description. This event may occur for multiple reasons.

Note   This event occurs when the diagnostic logging level of Availability Service is set to Low. For more information about how to change diagnostic logging levels, see Changing Process Logging Levels.

For more information about the root cause of this error, do one or more of the following:

• Increase the diagnostic logging level on the Availability Service and Availability Service General counter of the MSExchange Availability performance object. You can increase logging by running the following Exchange Management Shell commands:

  Set-EventLogLevel “MSExchange Availability\Availability Service” -Level High

  Set-EventLogLevel “MSExchange Availability\Availability Service General” -Level High

  For more information about increasing diagnostic logging levels, see How to Change Logging Levels for Exchange Processes.

• Review the Application event log for related events. Events that occur immediately before and after this event may provide more information about the root cause of this error.

  Important   After you have completed troubleshooting this issue, return logging to the default level by running the following commands:

  Set-EventLogLevel “MSExchange Availability\Availability Service” -Level Lowest

  Set-EventLogLevel “MSExchange Availability\Availability Service General” -Level Lowest

• If this event seems to be causing mail flow interruptions or other problems in the Exchange environment, contact Microsoft Product Support. For information about how to contact 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.