This article is contributed. See the original author and article here.

Note: Nominations for this program are now closed


We would like to have Exchange Online customers (who would like to participate in a preview program) help us improve the public folder hierarchy synchronization process. The preview program is called Hierarchy-Read-Replica (HRR) Preview.


Before we tell you more details of the HRR Preview program, you may want to read about the current public folder hierarchy synchronization here and then return to this post again.


Welcome back!


As you learned here, currently, the primary PF mailbox is the only source of hierarchy synchronization for all secondary PF mailboxes. This model can cause the following issues:



  • End-users might not be able to access public folder for hours, if on-boarding of public folders to Exchange online was just completed.

  • Hierarchy changes might not be synchronized to public folder mailboxes, which in turn might cause end-user issues like not being able to view or perform specific action on a public folder, even though user has required permissions.


As a solution to this problem, we are going in with a more distributed approach to propagate hierarchy changes, using a set of hierarchy-healthy secondary mailboxes and excluding them from serving hierarchy to end-users (which will dedicate them to hierarchy propagation tasks). This design will distribute the load from a single master mailbox to multiple mailboxes, hence improving overall performance.


The benefit you get by participating in the preview program is:



  • Be the early bird to be benefit from proposed improvements

  • Communicate directly with the engineering team


To join, you must meet the following eligibility criteria:



  • Public folders deployed in Exchange Online or public folder migration to Exchange Online nearing completion

  • Minimum of 100 public folder mailboxes in use


Sounds interesting? You can send us your nomination by filling in this form (link removed because nominations are closed), and we’ll contact you with further details.


Public Folder team

Brought to you by Dr. Ware, Microsoft Office 365 Silver Partner, Charleston SC.