Let’s talk about public folders. Do you use them? Do you use them for applications, repositories, newsgroup hosting, or discussion forums? This under-used feature of Exchange Server is often overlooked by organizations that focus on Exchange Server's messaging features.

Public folders within an organization or workgroup have some rather simplistic but powerful uses. For example, many organizations choose to deploy public folders as storage repositories for sharing files and documents. Other organizations take this a step further by using public folders as shared file systems (I don’t recommend this). You can also place key organizational or group documents in a public folder and let individuals share them, or set up public folders in a discussion group format where users post topical items for collaboration and discussion. Another scenario that some organizations find useful is to post an organizational contacts database in a public folder. For example, a small company’s sales team could store a customer contact list in a public folder where all sales team members could access it.

A more powerful use for the public information store (IS) is public folder applications. Public folder applications let users implement simple business processes via the Exchange Server. For example, an organization could use public folders to host an expense reimbursement process. Employees would use custom-developed forms to enter expense information and then submit the report for approvals and processing. The public IS stores the submitted items, and the Exchange Event Service provides some core business processing logic. When a user submits a new item, an event triggers to forward the item to the necessary approval authority and finally to accounting for final processing. With some additional work, many other more powerful applications are also possible by combining public folders and the Exchange Event Service.

You can also use Exchange Server public folders to host Internet-based or private newsgroups. In fact, some organizations take a public Internet news feed and dump it into the Exchange public IS. Messaging API (MAPI), Internet Message Access Protocol (IMAP), HTTP, and Network News Transfer Protocol (NNTP) clients can then access these newsgroups. You could even use Microsoft Outlook Express to access newsgroups via NNTP that are actually hosted by an Exchange Server.

Public folders are excellent repositories for static information. With a little more planning and management, they can also be excellent stores for simple applications and even newsgroups. If you haven’t made much use of public folders in your Exchange deployment thus far, you might want to take another look. There may be hidden potential on your Exchange Server just waiting for you to use.