One of the enhancements to Exchange Server 2007 with Service Pack 1 is the ability to view public folders when logged in to Outlook Web Access.

When an Exchange Server 2007 mailbox user attempts to open a public folder they may see the following information in the OWA window.

This will appear if the public folder database configured for use by mailboxes on the Exchange Server 2007 mailbox database does not contain any content. If the user clicks the “click here” link they are taken to the Exchange Server 2003 web-view of the public folder.

When Outlook Web Access accesses public folders from an Exchange 2007 SP1 mailbox, Outlook Web Access first tries to connect to an Exchange 2007 SP1 public folder store. If no Exchange 2007 SP1 public folder database is available, the Outlook Web Access server next tries to connect to an Exchange 2003 public folder store. When it connects, the user will see the public folder by using the Outlook Web Access 2003 UI.

Source (Microsoft Technet)

This behaviour will occur if the public folder store on the Exchange Server 2007 server has not been configured as a replica for that public folder. Although a public folder store on an Exchange Server 2007 server will hold the public folder hierarchy information, it will only perform public folder referrals to another server if it does not hold a local replica of the data. If that public folder referral results in the user being directed to an Exchange Server 2003 server, they will receive the prompt shown above.

To resolve this issue configure your Exchange Server 2007 public folder store to be a replica for the public folder content. You can view the current list of replicas for a public folder with the Get-PublicFolder cmdlet.

[PS] C:\>Get-Publicfolder "\NameOfFolder" | fl name,replicas

Name     : NameOfFolder
Replicas : {Public Folders}

To see all public folders you can do a recursive search.

[PS] C:\>Get-Publicfolder \ -Recurse | fl name,replicas

Name     : IPM_SUBTREE
Replicas : {}

Name     : NameOfFolder
Replicas : {Public Folders}

Name     : NameOfNextFolder
Replicas : {Public Folders}

Public folder replicas can be managed with the Set-Publicfolder cmdlet. The “replicas” attribute is multi-valued, and the Set-Publicfolder cmdlet will set it but not append to it, so you must include any existing replicas that you want to retain in the list.

[PS] C:\>Get-PublicFolder -recurse | Set-PublicFolder -Replicas "SERVER1\Public
 Folders","SERVER2\Public Folders","SERVER3\Public Folders"

The public folder content will replicate to the new replicas using the configured public folder replication interval. If you wish to do an update manually to speed things up you can use the Update-Publicfolder cmdlet.

Once the public folder store is listed as a replica and the content has replicated the Exchange Server 2007 SP1 mailbox users will be able to access the content in Outlook Web Access.

See also How to configure public folder replication.