|Message:||Process %1: Unable to find a public folder server for organizational unit (OU) %2. The service will attempt to find a random server, which may take a longer time to service the request.|
This Error event indicates that Microsoft® Exchange Availability service could not find a public folder server to retrieve the Schedule+ Free Busy data for one or more legacy Exchange mailboxes. A legacy Exchange mailbox refers to a mailbox that resides on an Exchange 2000 or Exchange 2003 server. The Exchange Availability service is responsible for retrieving Schedule+ Free Busy data for a set of mailboxes. If the mailbox resides on a computer that is running Exchange 2007 Server, the Availability service retrieves the data from the mailbox itself. However, if the mailbox resides on an Exchange 2000 or Exchange 2003 server, the Availability service retrieves the data from public folders. This event occurs when the Exchange Availability service does not locate a public folder server for legacy Exchange mailboxes. A public folder server is an Exchange server that has a public folder store. The organizational unit (OU) specified in the event description refers to an Administrative Group under which the Exchange server that is missing the public folder store is installed.
To resolve this error, make sure that the mailbox store that has legacy Exchange mailboxes points to a valid public folder store. You can confirm this by looking at the General tab of Mailbox Store Properties. For more information, see the following articles at the Microsoft Exchange Server TechCenter:
If you find that the required public folder store has been deleted or the mailbox store that has legacy Exchange mailboxes does not point to a valid public folder store, contact Microsoft Product Support Services. For more information, 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.