Topic Last Modified: 2010-04-26

The Microsoft Exchange Server 2010 Management Pack for System Center Operations Manager monitors the Windows Application log on computers running Exchange 2010 and generates this alert when the events specified in the following Details table are logged.

To learn more about this alert, in Operations Manager, do one or more of the following:


Product Name


Product Version

14.0 (Exchange 2010)

Event ID


Event Source


Alert Type


Rule Path

Microsoft Exchange Server/Exchange 2010/Mailbox/System Attendant

Rule Name

The directory object for this machine has the unexpected serverRole attribute value. OAB will not be generated by this server.


This Warning event indicates that a server that was designated to be the offline address book (OAB) generation server has an invalid value for the serverRole attribute in Active Directory. The Microsoft Exchange System Attendant service is responsible for generating the OAB. Before it begins generating the OAB, it checks the Active Directory server object to verify that the value for the serverRole attribute is set to the Mailbox role. If the value for the serverRole attribute is not set to the Mailbox role, this event is raised and OAB generation fails.

This alert may be caused if the serverRole attribute for the OAB generation server was manually changed to an invalid value or in the case of corruption in Active Directory. 

User Action

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

  • Designate another Mailbox server to be the OAB generation server. For more information about how to designate a different OAB generation server, see Move the Offline Address Book Generation Process to Another Server.

  • If you suspect corruption in Active Directory, investigate the event logs on your domain controllers for events that might give additional information on the state of your Active Directory databases.

If you are having difficulty resolving the issue, contact Microsoft Product Support. For information about contacting support, visit the Contact Us page of Microsoft Help and Support.

For More Information

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.