Most places and sites list how to add and remove permissions but few mention how to edit / modify existing permissions on the calendars.

In the below example we will grant Bob, Author rights on Arweth’s calendar.

Add-MailboxFolderPermission arweth@arweth.com:\Calendar -User bob@arweth.com -AccessRights Author

This is straight forward however if you want to edit the above permission or change the level of access you need to use the following command:

Set-MailboxFolderPermission arweth@arweth.com:\Calendar -User bob@arweth.com -AccessRights Editor

If you attempted to use the add-mailboxfolderpermission command again Office365 would have returned an error similar to:
An existing permission entry was found for user bob@arweth.com

As a note to remove a permission you use the command:

Remove-MailboxFolderPermission -Identity arweth@arweth.com:\calendar -user bob@arweth.com

You can also check existing permissions with the following command:

Get-MailboxFolderPermission -Identity arweth@arweth.com:\Calendar

You can also add the -user to the get command to return the permission for one user.

Hopefully this helps with the permission management of calendars – these commands will also work for other folders and in some versions of Exchange on Premise.

The post Office365 Calendar Permissions through PowerShell appeared first on Arweth.