We recently discovered an issue where, if you use Exchange Management Shell to configure custom access rights, the Free/Busy permissions do not get set at all (they remain as "None"):

$temp = [Microsoft.Exchange.Management.StoreTasks.MailboxFolderAccessRight[]]("ReadItems","EditOwnedItems","DeleteOwnedItems","EditAllItems","DeleteAllItems","FolderVisible")

Add-MailboxFolderPermission -Identity "conf-company-test:\calendar" -User "Company Calendar Management" -AccessRights $temp

Add-MailboxFolderPermission -Identity "conf-company-test:\calendar" -User "mpinkston" -AccessRights Editor

If you use a pre-defined "role" such as Editor given to mpinkston6 in the above example it sets the Free/Busy permission to Full Details. It would appear that using Add-MailboxFolderPermission or Set-MailboxFolderPermission is generic for folder objects, and doesn't explicitly set the Free/Busy permissions. In the case of the pre-defined roles either the command is doing something special/different, or the permission checks later accept pre-defined roles for determining Free/Busy permissions. No idea which is going on. If Free/Busy permissions can be fixed through PowerShell by some other mechanism/command, that would be great. If not, how do we go about requesting a fix/feature change in Exchange?

http://technet.microsoft.com/en-us/library/dd298062%28v=exchg.150%29.aspx
(Please expand Parameters and read AccessRights to get a better understanding for what I'm describing.)

Did you try adding AvailabilityOnly or LimitedDetails in your $temp variable for Calendar folder? These would set it to "Free/Busy time, subject, location" or "Free/Busy time" respectively....

Add-MailboxFolderPermission - http://technet.microsoft.com/en-us/library/dd298062(v=exchg.150).aspx

The following roles apply specifically to calendar folders:

• AvailabilityOnly   View only availability data

• LimitedDetails   View availability data with subject and location

Those are roles, and cannot be mixed with the other custom access rights. If you try, you'll get an error saying as much. Basically you can either set that AccessRights parameter to one of those pre-defined roles, or you can provide a comma delimited list of specific access rights, but not both.

Edit: Free/Busy permissions definitely get set by some other mechanism, as if you view the permissions with Get-MailboxFolderPermission before and after setting the Free/Busy permissions from the GUI, nothing changes.

• Edited by Matthew Pinkston Wednesday, January 14, 2015 2:12 AM

I found this article that attempts to demystify Free/Busy in Exchange, but it mainly covers Pre-Exchange 2007 technology, and I don't think it covers how permissions are managed. Does anyone have anymore information on this?

http://windowsitpro.com/exchange-server/freebusy-data-demystified

Thanks in advance!

Hi, were you able to figure out a solution or work-around for this?  I'm running into the exact same issue with Exchange 2013 and custom calendar permissions.