Deleting Public Folder Mailboxes

Question

So a week ago we tried to migrate our on premise public folders (Modern public folders) to exchange online using "Use Batch migration to migrate Exchange Server public folders to Exchange Online"

For whatever reason the migration couldn't complete and we had to "Revert back to on premise" but now we see a list of 5 new Public Folder Mailboxes on our on-premise exchange.

They all are Secondary Hierarchy and they all have 1.78MB of data. As per Microsoft they are saying that those were created by mistake and now can be deleted.

So, my question is can we safely delete them without causing any issues? has anyone seen anything like this before?

Answer 1

@Safs-3080

Check about "Public Folders" in ECP, if there doesn't exist Public Folder hosted on those Public Folder Mailbox, you will could delete them without issue. If there exist Public Folder on those Public Folder Mailbox for balance, I would suggest you move data and delete that folder first.

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Answer 2

You can run the below cmdlet to return and delete public folder mailboxes for the Secondary Hierarchy type:

Get-Mailbox -PublicFolder | where {$_.IsRootPublicFolderMailbox -eq $False} | Remove-Mailbox -PublicFolder

And for Primary Hierarchy type, you can use:

Get-Mailbox -PublicFolder | where {$_.IsRootPublicFolderMailbox -eq $true} | Remove-Mailbox -PublicFolder

Then you can go into ADSI and edit.

Browse to Configuration\Services \Microsoft Exchange\ {org name} and view the properties of the org.

Now Find msExchDefaultPublicFolderMailbox and clear it.

If the issue persists, you could shut down the server host PFs and mark sure it will not affect Exchange Online PFs. Then remove the Exchange server from ADSI.

I hope this will help you.