Applies to: Exchange Server 2010 SP3, Exchange Server 2010 SP2

Topic Last Modified: 2012-07-23

Public folder referrals have an associated cost number. The numbers range from 1 through 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 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.

Looking for other management tasks related to public folders? Check out Managing Public Folders.

Use the EMC to configure public folder referrals

You need to be assigned permissions before you can perform this procedure. To see what permissions you need, see the "Public folder databases" entry in the Mailbox Permissions topic.

  1. In the console tree, navigate to Organization Configuration > Mailbox.

  2. In the result pane, select the public folder database that you want to modify.

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

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

  5. 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.

    Note:
    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.
  6. To create a custom public folder referrals list and the associated costs, click Use custom list, click Add, and then perform following steps:

    1. Click Browse.

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

      Note:
      You can't select a server that's 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.
    3. In the Cost box, assign a cost number from 1 through 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.

  7. To add additional servers to the referral list, on the Public Folder Referral tab, click Add, and then repeat Steps a through c.

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

Use the Shell to configure public folder referrals

You need to be assigned permissions before you can perform this procedure. To see what permissions you need, see the "Public folder databases" entry in the Mailbox Permissions topic.

This example configures public folder referrals.

Copy Code 
Set-PublicFolderDatabase -Identity "Server1\PublicFolderDatabase01" -UseCustomReferralServerList $true -CustomReferralServerList "MBXSERVER01:1","MBXSERVER02:50"
Note:
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.