Microsoft Exchange public folders provide an excellent way to share heterogeneous types of information across large numbers of users in your organization. However, you can get the public folder data out to users more easily than simply having them use the standard Microsoft Outlook client.

Public folder databases
Exchange’s public folders offer a way to manage various types of data using the public information store database. Accessing the public folder databases in your infrastructure by using the Exchange Client or Microsoft Outlook is often adequate. That being said, Exchange 5.5 and 2000 both offer numerous ways to access the public (and private) information store data beyond Outlook.

Outlook Web Access (OWA)
Exchange 5.5 and 2000 offer Outlook Web Access (OWA) for accessing e-mail accounts via a Web browser. This is also the easiest way to get public folder data outside of Outlook or the Exchange client. OWA is respectable in Exchange 5.5 and is much improved with Exchange 2000. It provides an Outlook-like view in the browser and is a part of many remote access strategies as well as being useful for the connectivity of low bandwidth clients.

OWA requires authentication to access public folder data; this authentication enables Web clients to get to their private mailboxes. Depending on the browser used, OWA will provide a decent view of the public folders. Below are two screen shots of the same view (Public Folder – News) showing an OWA public folder view in Microsoft Internet Explorer 6 (Figure A) and Netscape Communicator 4.06 (Figure B). Notice that the older Netscape 4.06 platform does not display the preview pane in the browser and generally shows a less appealing view of the content.

Figure A
Public folders viewed from OWA with IE6

Figure B
Public folders viewed from OWA with Netscape 4.06

Installable File System (IFS)
Public folders and private information stores can also be accessed through the Windows Installable File System (IFS). This technology functions as a filing system that makes private mailboxes and the public information stores available to Windows clients via drive mapping or from the Windows Explorer.

A default Exchange 2000 Server installation places the IFS on the M: drive of that machine. Access is then controlled via sharing, as with other Windows resources. IFS provides the public folder contents as files and folders. This is an interactive session, and it is not read-only or offline access (though ACLs can dictate otherwise). IFS allows direct interaction with the public information store through this folder.

In my test network, I set up a top-level public folder called News and shared it by going into the M:\<Domain Name>\ Public Folders directory and enabling the share on the Exchange server, as shown in Figure C.

Figure C
Sharing public folders like file shares

In this example, the public folder itself is named News. I named the share E2K-PF-News to tell me that it is an Exchange 2000 public folder called News. Once the share is created, it is viewable in Windows Explorer and drives can be mapped from clients. Unlike other drives in Windows, the M:\ drive does not have an administrative secret share (for example, \\servername\m$) created by default.

Once a drive is mapped, you can view all of the public folder objects in the Windows Explorer. Mail messages, for example, show up as .eml mail message items, and when you open them by default in Windows 2000 and XP, they open in Outlook Express. Figure D shows a view of my mapped drive to the public folder.

Figure D
Public folders viewed from Windows Explorer

Web Sharing
Another approach is to use the Web Sharing option. Web Sharing takes the IFS contents and associates them with an Internet Information Services (IIS) alias directory. When doing this (Figure E), the contents of the public folder are displayed (very simply) in a Web browser, as shown in Figure F. This configuration is different from Outlook Web Access because the interface displays the contents with less formatting, although HTML and other message formats display with their associated formatting.

Figure E
Configuring Web Sharing for public folders

Figure F
Viewing public folders via Web Sharing

I see Web Sharing as an excellent option for organizations that have users who don’t have e-mail accounts but who need access to public folder data. A warehouse or manufacturing environment might fall into this category. Web Sharing can be configured to require no authentication to the public folder areas you enable, making it a good solution for terminals where multiple employees browse company data.

The Web Sharing option can display large amounts of public folder data and use minimal system resource. For example, I imported the 18 months of messages (approximately 10,000 messages) into one public folder, and it displays nearly instantly on my Pentium 166 server with 96 MB of RAM.

Application programming interfaces (APIs)
For a custom programming solution, the Exchange information store architecture supports programming calls directly to the public folder storage groups. These can exist as Active Directory Services Interfaces, ActiveX Data Objects, Collaboration Data Objects, and OLE DB, among others. Solutions of this nature can help you deliver exactly what you need from public folders to the user or directly to another system.

Other options
There are more options that give online and offline access to public folder (and other Exchange) data. Various tools can pull public folder data into Microsoft Access or other database software, for example. Some commercial non-Outlook Exchange client software packages can also handle public folders, although in the last few years, I have found that those are getting harder to find.

Final word
The bottom line here is that public folders can be a valuable resource for collaboration and company communications—and you don’t have to be limited to simply accessing them from Outlook. The examples I have given are all easy to implement. Just be careful not to overexpose parts of your Exchange databases if you experiment with these methods on your production network.

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