Topic Last Modified: 2008-11-21

This topic provides information about how to troubleshoot an issue with the Availability service that may occur after users are migrated from Microsoft Exchange Server 2003 to Microsoft Exchange Server 2007. The Availability service for Exchange Server 2007 provides calendar information for users. This information is known as free/busy information.

After users are migrated from Exchange Server 2003 to Exchange Server 2007, users may be unable to view free/busy information. This issue may occur if the system attendant mailbox is disconnected. 

To determine whether the system attendant mailbox is disconnected, view the Application log in Event Viewer on the Exchange Server 2007 computer, and then locate the following event:

Event Type: Warning

Event Source: MSExchangeSA

Event Category: General

Event ID: 9159


Microsoft Exchange System Attendant has detected that the system attendant object in the DS has been modified. System Attendant needs to restart the Microsoft Exchange Free Busy Publishing Service.

Before You Begin

To perform this procedure, the account you use must be delegated the following:

  • membership in the local Administrators group

For more information about permissions, delegating roles, and the rights that are required to administer Exchange Server 2007, see Permission Considerations.


To correct this error

  1. Start ADSI Edit.

  2. Expand the following container:

    Domain [<ServerName>.<DomainName>.<RootDomain>]/DC=<DomainName>,DC=<RootDomain>/CN=Users.

  3. Right-click a suitable user object, and then click Properties. For example, right-click CN=User1, and then click Properties.

  4. In the Attributes list, click homeMDB, and then click Edit.

  5. Copy the entry in the Value box to the Clipboard so that you can use it in step 9.

  6. Click Cancel two times.

  7. In ADSI Edit, expand the following container:

    Configuration [<Server_Name>.<Domain_Name>.<Root_Domain>]/ CN=Configuration,DC=< Server_Name >DC=<Domain>,DC=<RootDomain>/CN=Services/CN=Microsoft Exchange/CN=<OrganizationName>/CN=Administrative Groups/CN=<FirstAdministrativeGroup>/CN=Servers/CN=<TargetServerName>.

  8. Right-click CN=Microsoft System Attendant, and then click Properties.

  9. In the Attributes list, click homeMDB, and then click Edit.

  10. In the Value box, paste the text that you saved to the Clipboard in step 5, and then click OK two times.

  11. Close ADSI Edit.