allowing Exchange Online users to see on-premise public folders?

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Hi I have been reading this document: as we have on-premise public folders which we would like Exchange Online users to see. Our current environment is Exchange 2016 but I believe that document is still applicable.


Heres the problem:

Not all our public folders are mail-enabled.. so I am wondering if this still works? another questions I have is regarding the command listed in that article "Set-OrganizationConfig -PublicFoldersEnabled Remote -RemotePublicFolderMailboxes PFMailbox1,PFMailbox2,PFMailbox3" Am I right in thinking that the command referes to the public folder mailboxes and not the individual public folders? so for instance if I had a public folder mailbox called "PFSales" and another called "PFMarketing"to make this public folder viewable to Exchange online users I would run 

Set-OrganizationConfig -PublicFoldersEnabled Remote -RemotePublicFolderMailboxes PFSales,PFMarketing" ?

4 Replies



Yes, it is still applicable for Exchange 2016 as well. You don't have to mail-enable all your public folders for accessing them from an Exchange Online mailbox. The synchronization of mail-enabled public folders is only for mail flow purposes, like that your users can see them in the GAL.


The Set-OrganizationConfig determines the public folder (proxy) mailboxes to get access through Autodiscover to your on-premises organization, right.


Referencing this document: Configure Exchange 2013 public folders for a hybrid deployment which I have been told is applicable to Exchange 2016 also. I am confused on these steps as i have found them not to work, so maybe I am doing something wrong so et me break down what I am doing step by step


I download the script listed in that document and place if on my exchange server:


  • Sync-MailPublicFolders.ps1

I then run Sync-MailPublicFolders.ps1 -Credential (Get-Credential)  -CsvSummaryFile:sync_summary.csv


I then go to Exchange online powershell and run


Set-OrganizationConfig -PublicFoldersEnabled Remote -RemotePublicFolderMailboxes PFMailbox1,PFMailbox2,PFMailbox3


where PFmailbox is the name of the mailboxes on-premise


this results in absolutely nothing happening..


It seems good but it can take a couple of hours.

If you connect from an external network, make sure MAPI/http is configured and published correctly. The Autodiscover process from your Exchange Online organization will "find" the on-premises public folder mailboxes you configured in the Exchange Online Set-OrganizationConfig.


If you are using alternate login id, which means your UPN is not your primary smtp address, make sure modern authentication is enabled in Exchange Online for accessing public folders in your hybrid environment.


If the mailbox for the user was created in Exchange Online and doesn't have an associated on-premises user object for authentication to the public folder then the exchange online users won't be able to see on-premise public folders.


In order to allow Exchange Online users to see on-premise public folders Exchange Online mailbox must be linked to an on-premises user account. Please go through the below article to get this acheived: