Manage Exchange 2010 Calendar Permissions Using Powershell

In this example we will add a domain group named group-calendarReviewers to a mailbox named Jeremy.Whittaker.  We will give the group “Reviewer” access rights
Add-MailboxFolderPermission -identity “Jeremy.Whittaker:calendar” –user “DomainNamegroup-calendarReviewers” -AccessRights Reviewer
In this example above I use reviewer.  However, instead of using “Reviewer” permissions you may choose from all these different types of permissions:
None                                                   FolderVisible
Owner                                                CreateItems, ReadItems, CreateSubfolders, FolderOwner, FolderContact, FolderVisible, EditOwnedItems, EditAllItems, DeleteOwnedItems, DeleteAllItems
PublishingEditor                       CreateItems, ReadItems, CreateSubfolders, FolderVisible, EditOwnedItems, EditAllItems, DeleteOwnedItems, DeleteAllItems
Editor                                                 CreateItems, ReadItems, FolderVisible, EditOwnedItems, EditAllItems, DeleteOwnedItems, DeleteAllItems
PublishingAuthor                    CreateItems, ReadItems, CreateSubfolders, FolderVisible, EditOwnedItems, DeleteOwnedItems
Author                                              CreateItems, ReadItems, FolderVisible, EditOwnedItems, DeleteOwnedItems
NonEditingAuthor                   CreateItems, ReadItems, FolderVisible
Reviewer                                          ReadItems, FolderVisible
Contributor                                   CreateItems, FolderVisible
 
The following roles apply specifically to calendar folders:
 
AvailabilityOnly                        View only availability data
LimitedDetails                            View availability data with subject and location
Now lets say you want to go through all the users in your domain and give the group group-calendarReviewers permissions to everyones calendar:
{codecitation}$users = Get-mailbox
$users | ForEach-Object {
Set-MailboxFolderPermission $_”:Calendar” -User Default -AccessRights AvailabilityOnly
Remove-MailboxFolderPermission $_”:Calendar” -User “DomainNamegroup-calendarReviewers” -Confirm:$False
Add-MailboxFolderPermission $_”:Calendar” -User “DomainNamegroup-calendarReviewers” -AccessRights Reviewer
}$users = Get-mailbox $users | ForEach-Object {{codecitation}