Exchange Restrict Room Mailbox Booking For A Certain Group

We recently migrated from Notes to Exchange 2016, and while most users are happy with the way Exchange/Outlook works, some don't want to change and like the way Notes used to handle certain things; like who has access to book meetings rooms. The problem is: it creates more work because as the Exchange administrator, I have to now individually manage each room instead of letting the booking delegates do it, but oh well :)

Luckily with PowerShell, settings booking permissions is simple!

First, create a Security Group and add the members who will be allowed to book a room. Yes, you can create a distribution group, but I prefer to use security groups when assigning permissions to anything...I'm also OCD about keeping my AD/Exchange clean ;)

Once you have your group built, lets call it "Room 1 Allowed" run the following cmdlets in the Exchange Management Shell (EMS):

Set-CalendarProcessing "Room 1" -AllBookInPolicy $false

Set-CalendarProcessing "Room 1" -RequestInPolicy $none

Set-CalendarProcessing "Room 1" -BookInPolicy "Room 1 Allowed"

**Note** Change "Room 1" to the name of your Room Mailbox.

To see the permissions on the Room calendar, run:

Get-CalendarProcessing "Room 1" | fl

You should see that the Security Group you added in the "BookInPolicy" is in there.

Now, have a member of the group try to book the room and it will be successful. And have someone not in the group try, and they'll get a warning message saying the meeting was rejected because they aren't allowed.