Removed Default or Anonymous permission for Outlook folders can't be restored in an Exchange Server 2013 environment
Original KB number: 2983066
Symptoms
After you remove the Default or the Anonymous permission from a Microsoft Outlook folder in an Exchange Server 2013 environment, you can't add the permissions back by running the Add-MailboxFolderPermission cmdlet in Exchange Management Shell (EMS).
Note
When you run the Add-MailboxFolderPermission cmdlet to add the permissions back, the result indicates that the operation succeeds. Actually, when you run the Get-MailboxFolderPermission cmdlet, the permissions are not added as expected.
Resolution
To resolve this issue, install the following cumulative update:
Cumulative Update 6 for Exchange Server 2013
Note
We don't recommend removing the Default or the Anonymous permission from an Outlook folder.
Cause
This issue occurs because the Add-MailboxFolderPermission cmdlet doesn't set the Access rights parameter correctly.
Status
Microsoft has confirmed that this is a problem.
More information
By default, the Anonymous and the Default accounts have the Access rights parameter set to None on every folder in an Exchange Server 2013 mailbox.
Here is a sample of the result when you run the Get-MailboxFolderPermission cmdlet for default settings in EMS:
[PS] C:\>Get-MailboxFolderPermission usermbx:\inbox
FolderName User AccessRights
---------- ---- ------------
Inbox Default {None}
Inbox Anonymous {None}