Doing a bit of migration work for clients at the moment, and one of the things we are striking with one of the projects are limitations on Public Folders. I hear you ask “What limits on Public Folders??” Well Microsoft has some time after the release of Exchange 2013 decided to publish what they call supported limits on Public Folders. Note that to the best of my knowledge they have not published any limits on Exchange 2010 public folders so people on Exchange 2010 are likely totally oblivious to these limitations for their public folder structures. That in itself represents a major problem, but we’ll talk about that in another post later.
Anyway – further research has shown that Microsoft has listed limitations not only for Public Folders on Exchange 2013, but also for Exchange 2016 and Exchange Online / Office 365 as well. The links below are to the current documentation – Note that they might well change, so keep an eye on them for the future.
- Exchange 2013 Public Folder Limits
- Exchange 2016 Public Folder Limits
- Exchange Online / Office 365 Public Folder Limits
Now doing further research on this topic, I’ve found some interesting information online that talks about why these limits exist now vs before. The conclusion that most have come to understand is that Microsoft have decided on limits like this because the new Exchange 2013/2016 architecture has been redesigned in a way to “fit” into the Exchange 2013/2016 DAGS implementation so they can provide for high availability. That is to say, they were some time back going to deprecate Public Folders entirely, and for a while Exchange 2013 was not going to have Public Folders at all, which Microsoft later relented on. Therefore this is the way they shoehorn things into the Exchange system given they didn’t really design it to handle public folders in the first place.