• If the name of a folder in the mailbox has a backslash in it then you can't view or change permissions - this is a limitation of the PowerShell commands for modifying permissions.
  • You might see a user called Anonymous show up on some folders - don't try and change any permissions or remove it. I'm not entirely sure what it does but i'm pretty sure it's important, so leave it alone.
  • You'll notice when you select the Top Of Information Store folder the Folder & Subfolders button is only available if you select Remove in the permissions drop down. This is by design - it's a bad idea to add a user to every folder in the mailbox.
  • The EWS API can sometimes be a bit screwy when it comes to adding or removing delegates and occasionally it can leave them in an inconsistent state which has required removing them from the user's Outlook.
  • When you add a new delegate then by default they will also be given Editor access to the calendar and None to the Inbox, Tasks, Contacts, Notes and Journal folders. This will replace any existing permissions to those folders that the user already has, so check before adding delegates.
  • Lastly, I made this because it is useful to me, and I hope it can be useful to others, but you shouldn't use it unless you know what you are doing - it can be very easy to screw up permissions on a mailbox. You should also make sure people are aware that you are changing permissions on their mailbox, or you might have some difficult explaining to do.