Calendar Permissions

Exchange Online – Calendar Permissions & Processing

This page provides a consolidated reference for managing calendar access, delegation, and processing in Exchange Online using PowerShell.

📘 Connecting to Exchange Online

Before running any calendar commands, connect to the Exchange Online PowerShell module:

Connect-ExchangeOnline -UserPrincipalName [email protected]

👁 View Calendar Permissions

List current permissions for a user’s primary calendar:

Get-MailboxFolderPermission "UserName:\Calendar"

View calendar permissions for all users:

Get-Mailbox -RecipientTypeDetails UserMailbox | ForEach-Object {
    Get-MailboxFolderPermission "$($_.PrimarySmtpAddress):\Calendar" | Select Identity, User, AccessRights
}

➕ Add Calendar Permissions

Permission Type	Command Example	Description
Reviewer	`Add-MailboxFolderPermission "UserName:\Calendar" -User [email protected] -AccessRights Reviewer`	Can view full details of calendar items
Editor	`Add-MailboxFolderPermission "UserName:\Calendar" -User [email protected] -AccessRights Editor`	Full read/write control
AvailabilityOnly	`Add-MailboxFolderPermission "UserName:\Calendar" -User [email protected] -AccessRights AvailabilityOnly`	Shows free/busy info only
LimitedDetails	`Add-MailboxFolderPermission "UserName:\Calendar" -User [email protected] -AccessRights LimitedDetails`	Shows time, subject, and location

➖ Remove Calendar Permissions

Remove-MailboxFolderPermission "UserName:\Calendar" -User [email protected]

Remove all permissions for a specific calendar:

Get-MailboxFolderPermission "UserName:\Calendar" | Where-Object {$_.User -ne "Default" -and $_.User -ne "Anonymous"} | ForEach-Object {
    Remove-MailboxFolderPermission "UserName:\Calendar" -User $_.User
}

🔁 Modify Existing Permissions

Change a user’s calendar access level:

Set-MailboxFolderPermission "UserName:\Calendar" -User [email protected] -AccessRights Reviewer

👥 Default & Anonymous Permissions

Set what all internal users or external users see:

Set-MailboxFolderPermission "UserName:\Calendar" -User Default -AccessRights AvailabilityOnly
Set-MailboxFolderPermission "UserName:\Calendar" -User Anonymous -AccessRights None

Check existing defaults:

Get-MailboxFolderPermission "UserName:\Calendar" | Where-Object {$_.User -eq "Default" -or $_.User -eq "Anonymous"}

🧩 Delegate Access (Send on Behalf / Manage Meeting Requests)

Add Delegate

Add-MailboxFolderPermission "Manager:\Calendar" -User [email protected] -AccessRights Editor
Set-Mailbox -Identity "Manager" -GrantSendOnBehalfTo [email protected]

Remove Delegate

Remove-MailboxFolderPermission "Manager:\Calendar" -User [email protected]
Set-Mailbox -Identity "Manager" -GrantSendOnBehalfTo $null

⚙️ Calendar Processing Settings

Control automatic meeting request processing:

View Current Settings

Get-CalendarProcessing "UserName"

Enable Auto-Accept and Decline Conflicts

Set-CalendarProcessing "UserName" -AutomateProcessing AutoAccept -AddOrganizerToSubject $true -DeleteComments $false -DeleteSubject $false -AddAdditionalResponse $true

Disable Auto-Processing (Manual)

Set-CalendarProcessing "UserName" -AutomateProcessing None

Resource Mailboxes (Rooms/Equipment)

Set-CalendarProcessing "Room Name" -AutomateProcessing AutoAccept -AllowConflicts $false -BookingWindowInDays 180 -EnforceSchedulingHorizon $true

📊 Quick Reference Summary

Task	Command	Notes
View calendar permissions	`Get-MailboxFolderPermission "User:\Calendar"`	Lists all assigned permissions
Add Reviewer	`Add-MailboxFolderPermission "User:\Calendar" -User [email protected] -AccessRights Reviewer`	Grant read-only view
Remove Access	`Remove-MailboxFolderPermission "User:\Calendar" -User [email protected]`	Removes user access
Default Availability	`Set-MailboxFolderPermission "User:\Calendar" -User Default -AccessRights AvailabilityOnly`	Default org-wide setting
Auto Accept Meetings	`Set-CalendarProcessing "User" -AutomateProcessing AutoAccept`	Enables auto-acceptance
View Calendar Processing	`Get-CalendarProcessing "User"`	Check resource or user mailbox rules

🧰 Tips

To apply settings across multiple mailboxes:

Get-Mailbox -RecipientTypeDetails UserMailbox | ForEach-Object {
    Set-CalendarProcessing $_.Alias -AutomateProcessing AutoAccept
}

Always verify changes with:

Get-MailboxFolderPermission "User:\Calendar"

Updated: {{ date }}
Author: Tomas Toohey
Reference Category: Exchange Quick References