Microsoft Exchange Server 2007 Administrators Pocket Consultant Second Edition

You use public folders to share messaging content and documents within an organization. Public folders are stored in a hierarchical structure referred to as a public folder tree. There is a direct correspondence between public folder databases and public folder trees. Each Mailbox server in a Microsoft Exchange 2007 organization can have one public folder database, and all Mailbox servers share the same public folder tree, referred to as the default public folder tree. Exchange 2007 does not support alternate public folder trees. If you want users to have access to alternate public folder trees, you must retain a computer running Exchange 2000 Server or Exchange Server 2003 in your Exchange 2007 organization.

Accessing Public Folders

When your Exchange 2007 organization has more than one public folder database, Mailbox servers replicate public folder data automatically between and among these databases to create public folder replicas. Replicas provide redundancy in case of server failure and help to distribute the user load. All replicas of a public folder are equal. There is no master replica. This means that you can directly modify replicas of public folders. The Mailbox server with which you are working replicates the folder changes automatically to other servers.

Public folder trees define the structure of an organization's public folders. The default public folder tree has its own hierarchy, which you can make accessible to users based on criteria you set. E-mail clients, such as Microsoft Outlook 2003, can access public folders using Messaging Application Programming Interface (MAPI). Newer clients, such as Outlook 2007, can access public folders using Hypertext Transfer Protocol (HTTP). The actual technology that makes it possible to create, edit, and manage messaging content and documents on remote servers is Web Distributed Authoring and Versioning (WebDAV).

To maintain security, each public folder can have specific usage rules. For example, you could create public folders called CompanyWide, Marketing, and Engineering. Whereas you would typically make the CompanyWide folder accessible to all users, you would make the Marketing folder accessible only to users in the marketing department, and the Engineering folder accessible only to users in the engineering department.

Accessing Public Folders in Mail Clients

You can access public folders from just about any e-mail client, provided the client is MAPI-compliant or supports Web distribution points, such as Outlook 2007. When you configure Outlook 2007 for Exchange Server, users have direct access to the default public folders tree. When you configure Outlook 2007 for Internet-only use, users can access public folders using only Internet Messaging Access Protocol 4 (IMAP4), and you must have retained a computer running Exchange 2000 Server or Exchange Server 2003 in your Exchange 2007 organization.

If Outlook is configured properly, users can access public folders by completing the following steps:

1. Start Outlook 2007. If the Folder list isn't displayed, click Go, and then select Folder List.

2. In the Folder list, expand Public Folders, and then expand All Public Folders to get a complete view of the available top-level folders. A top-level folder is simply a folder at the next level below the tree root.

Accessing Public Folders Through the Information Store

Exchange 2007 automatically configures Web sharing and access controls. As an administrator, you can access public folders through the Exchange information store. As no graphical management interfaces are provided for accessing public folders in Exchange Management Console, you must use the Exchange Management Shell to do this.

At the Exchange Management Shell prompt, you can get information about the public folder database by using the Get-PublicFolder cmdlet. When you are working with this cmdlet, you use the –Identity parameter to identify the folder with which you want to work:

• ∖ represents the root public folder (also known as the IPM_SUBTREE).

• ∖FolderName represents a specific, named folder.

• ∖NON_IPM_SUBTREE represents the hidden system folder root.

Sample 14-1 provides the syntax and usage for getting information about a folder. As the sample output shows, Exchange Management Shell returns configuration details for the folder identity.

Sample 14-1: Getting information about a public folder

Syntax Get-PublicFolder -Identity 'FolderIdentity' Usage Get-PublicFolder -Identity '\' Output Schema : Microsoft.Exchange.Data.Mapi.PublicFolderSchema AgeLimit : EntryId : HasSubFolders : True HiddenFromAddressListsEnabled : False LocalReplicaAgeLimit : MailEnabled : False MaxItemSize : 102040 KB Name : IPM_SUBTREE ParentPath : PerUserReadStateEnabled : True PostStorageQuota : Replicas : {} ReplicationSchedule : {} RetainDeletedItemsFor : 90 days StorageQuota : UseDatabaseAgeDefaults : True UseDatabaseQuotaDefaults : True UseDatabaseReplicationSchedule : False UseDatabaseRetentionDefaults : True Identity : \ ObjectState : Unchanged IsValid : True MapiSession : Microsoft.Exchange.Data.Mapi.MapiMessageStoreSession

You can use the –Recurse parameter to examine recursively the folder and its sub-folders. When you use this parameter, you must redirect the output through the Format-List command and name the folder details that you want to examine. You can examine any of the properties previously listed in Sample 14-1 by specifying the property names to return in a comma-separated list. For example, if you want to return a list of all sub-folders of the public folder root formatted by the Name and MailEnabled properties, you could use the following command:

Get-PublicFolder -Identity '\' -Recurse | Format-List Name, MailEnabled

The output would look similar to the following:

Name : IPM_SUBTREE MailEnabled : False Name : Projects MailEnabled : False Name : SavedData MailEnabled : False Name : Teams MailEnabled : False

If you suspect there is a replication problem with public folders, you could compare the configuration details for public folders on your Mailbox servers using the Get-PublicFolder cmdlet. Just specify the –Server parameter and the identity of the server you want to work with, such as:

Get-PublicFolder -Server 'CorpSvr272'

To get information about a specific server's public folder configuration, you can use the –Server parameter to identify the server with which you want to work.

Get-PublicFolder -Identity '\' -Server 'CorpSvr272'

Real World You can trace most problems with Web sharing of public folders to individuals who inadvertently change the access settings. If you restore the original settings, users should regain access to the public folder. Note that only Exchange Server can initialize Web sharing for public folders. If Exchange Server isn't sharing public folders correctly, you might have incorrectly configured Microsoft Internet Information Services (IIS) or Outlook Web Access. For details on working with IIS, HTTP virtual servers, and Outlook Web Access, see Chapter 16, "Managing Client Access Servers."