Applies to: Exchange Server 2007 SP3, Exchange Server 2007 SP2, Exchange Server 2007 SP1
Topic Last Modified: 2007-08-27

Public folder referrals have an associated cost number. The numbers range from 1 to 100. This cost number is used to optimize message flow. Specifically, e-mail messages are routed according to lowest cost number. If two or more routes are available with the same cost, the load is distributed as equally as possible between them. This cost is also used to calculate the most appropriate route that the client application (such as Microsoft Office Outlook) can use to access public folders on remote servers.

The maximum public folder referral cost that you can set for a public folder database is 100. However, by setting the maximum referral cost for a server to 100, the server may still be used for referrals. If you want to decrease the chances of the server being used for referrals, you should work with your domain administrator or enterprise administrator to configure site link costs.

For more information about the Active Directory directory service sites in Windows Server 2003, see Sites Overview. For more information about how to configure site link costs in Windows Server 2003, see Configure site link cost. For information about the sites and services in Active Directory Domain Services (AD DS) for Windows Server 2008, see "Understanding Sites, Subnets, and Site Links" in Windows Server 2008 Help.

This topic explains how to use the Exchange Management Console or the Exchange Management Shell to configure costs for public folder referrals. In addition, you can configure the custom referral cost list to not use certain servers by excluding them from the list.

Before You Begin

To perform this procedure in Microsoft Exchange Server 2007 SP1, the account you use must be delegated the following:

  • Exchange Public Folder Administrator role and local Administrators group for the target server

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

Also, before you perform this procedure, be aware of the following:

  • After you configure the cost referrals for public folders, you are required to maintain the list of cost referrals. Therefore, you must make sure that each new public folder database is added to the referral list as needed.

  • You cannot perform this procedure in the release to manufacturing (RTM) version of Exchange 2007. You must have Exchange 2007 Service Pack 1 (SP1) installed. To download SP1 for Exchange 2007, see Exchange Server 2007 Service Pack 1.


To use the Exchange Management console to configure a specific list of servers and costs for public folder referrals

  1. Start the Exchange Management Console.

  2. In the console tree, expand Server Configuration, and then click Mailbox.

  3. In the work pane, select the public folder database that you want to modify.

  4. In the action pane, under the name of the public folder database, click Properties.

  5. In <Public Folder Database> Properties, click the Public Folder Referral tab.

  6. To specify that Exchange uses the cost data from the Active Directory site to compute the connection cost for public folder referrals, click Use Active Directory site costs. This is the default option.

    If the custom list contains public folder referrals and you click Use Active Directory sites costs, the list is unavailable and is cleared when this tab is refreshed.
  7. To create a custom public folder referrals list and the associated costs, click Use custom list, and then click Add.

  8. In Server Referral Cost, click Browse.

  9. In Select Referral Server, select the Mailbox server on which a public folder database resides, and then click OK.

    You cannot select a server that is already in the list of servers that appear in the Name column on the Public Folder Referral tab, nor can you select the server on which the specified public folder database resides.
  10. In Server Referral Cost, in the Cost box, assign a cost number between 1 and 100, and then click OK. The number 1 represents the lowest cost, which means that Exchange routing is more likely to use this as the replica server. The number 100 represents the highest cost, which means that Exchange routing is less likely to use this as the replica server.

  11. To add additional servers to the referral list, on the Public Folder Referral tab, click Add, and then repeat Steps 8 through 10.

  12. Click OK to close <Public Folder Database> Properties.

To use the Exchange Management Shell to configure a specific list of servers and costs for public folder referrals

  • Run the following command.

    Copy Code
    Set-PublicFolderDatabase -Identity "Server1\PublicFolderDatabase01" -UseCustomReferralServerList $true -CustomReferralServerList "MBXSERVER01:1","MBXSERVER02:50"
    The CustomReferralServerList parameter accepts an array in the following format: serverID:cost. Separate multiple servers with a comma.

For detailed syntax and parameter information, see Set-PublicFolderDatabase.

For More Information

To learn more about public folders, see Understanding Public Folders.

For more information about managing public folders, see the following topics: