EDIT 3/31/2008: We have posted the updated public folder guidance for versions of Exchange past Exchange 2007; you might want to read it.
A frequent topic of discussion with customers is the future of Public Folders, thus I think it would be good to capture that discussion on our blog.
Architecturally, Public Folders are a special mailbox, like all other mailboxes having a single top level folder hierarchy, but unlike all other mailboxes, Public Folders are stored in a dedicated database whose content can be replicated between servers. Administrators centrally manage this folder hierarchy, enabling end-users to create and modify folder content as they see fit.
Public Folders were introduced in the first version of Exchange as a solution for sharing, discussion list archives, and as a platform for custom applications.
All current versions of Outlook (from 97 through 2003) also use Public Folders for four very important functions:
1) Offline address book distribution
2) Free/busy lookups
3) Organizational form library
4) Outlook Security settings
With Exchange 2003 SP2, we invested in the manageability of Public Folders. A quick list of improved controls for administrators includes:
1) stop and resume content replication
2) apply delta changes recursively through a hierarchy
3) synchronize the hierarchy
4) ensure safe movement and/or removal of servers and stores
5) log public folder deletions
Alongside SP2 we also shipped PFDavAdmin, which in addition to being a great tool for managing Public Folder permissions, addresses a very common customer request: how should you identify which public folders are stale (with the goal of deleting them/cleaning them up)? Unfortunately, virus scanning software accesses Public Folder content frequently, and current versions of Exchange do not have a good way to distinguish AV reads vs. end-user reads. We do however, have a clear understanding of when content was last modified. PFDavAdmin clearly identifies when Public Folder replicas and content has been last modified. If nothing has changed in 5 years, how interesting can it be?
As mentioned in the summary, Outlook 2007 and E12 will include support for Public Folders. Of course, there are some details worth noting:
We are "de-emphasizing" Public Folders - which means that Public Folders may not be in our next major release after E12. That being said, let me re-affirm our commitment to fully support E12 Public Folders through at least 2016.
With this de-emphasis, we understand that some customers will be seeking prescriptive guidance on managing their Public Folder deployments. We will post more here soon. In the mean time, I recommend:
- Terry Myerson