Calendar Processing

This page provides a quick reference for managing calendar processing, meeting requests, and resource mailbox rules in Exchange Online using PowerShell.

📘 Connecting to Exchange Online

Connect-ExchangeOnline -UserPrincipalName [email protected]

⚙️ View Current Calendar Processing Settings

Check the configuration for a specific mailbox or resource:

Get-CalendarProcessing -Identity "MailboxName"

Common output fields include:

AutomateProcessing — how meeting requests are handled (AutoAccept, AutoUpdate, None)
AddOrganizerToSubject — whether the organizer’s name is added to the meeting subject
AllowConflicts — allows overlapping bookings (for shared rooms/resources)
BookingWindowInDays — how far in advance bookings are accepted
EnforceSchedulingHorizon — restricts bookings beyond the allowed window
AddAdditionalResponse — adds a custom response to meeting invitations

🧩 Configure Automatic Meeting Processing

Enable AutoAccept for a Mailbox

Set-CalendarProcessing -Identity "MailboxName" -AutomateProcessing AutoAccept

Disable Automatic Processing (Manual Approval Required)

Set-CalendarProcessing -Identity "MailboxName" -AutomateProcessing None

Update Organizer Information in Subject Line

Set-CalendarProcessing -Identity "MailboxName" -AddOrganizerToSubject $true -DeleteComments $false -DeleteSubject $false

🏢 Resource Mailbox Configuration (Rooms & Equipment)

Enable Automatic Booking

Set-CalendarProcessing -Identity "RoomName" -AutomateProcessing AutoAccept -AllowConflicts $false -BookingWindowInDays 180 -EnforceSchedulingHorizon $true

Allow Conflicts (e.g., Shared Spaces)

Set-CalendarProcessing -Identity "RoomName" -AllowConflicts $true

Set Custom Booking Responses

Set-CalendarProcessing -Identity "RoomName" -AddAdditionalResponse $true -AdditionalResponse "Your meeting has been auto-accepted by Fusion Reference System."

Disable Automatic Responses

Set-CalendarProcessing -Identity "RoomName" -AddAdditionalResponse $false

🧭 Check Room Mailbox Settings for All Rooms

List all resource mailboxes with auto-accept enabled:

Get-Mailbox -RecipientTypeDetails RoomMailbox | Get-CalendarProcessing | Where-Object {$_.AutomateProcessing -eq "AutoAccept"} | Select Identity, AutomateProcessing, BookingWindowInDays, AllowConflicts

🧰 Common Scenarios

1. Enforce Booking Rules for All Rooms

Get-Mailbox -RecipientTypeDetails RoomMailbox | ForEach-Object {
    Set-CalendarProcessing -Identity $_.PrimarySmtpAddress -AutomateProcessing AutoAccept -AllowConflicts $false -BookingWindowInDays 180 -EnforceSchedulingHorizon $true
}

2. Enable Custom Response on All Room Mailboxes

Get-Mailbox -RecipientTypeDetails RoomMailbox | ForEach-Object {
    Set-CalendarProcessing -Identity $_.PrimarySmtpAddress -AddAdditionalResponse $true -AdditionalResponse "Your meeting has been auto-accepted by Fusion Reference System."
}

3. Verify All Room Mailbox Configurations

Get-Mailbox -RecipientTypeDetails RoomMailbox | Get-CalendarProcessing | Select Identity, AutomateProcessing, AllowConflicts, BookingWindowInDays

📊 Quick Reference Summary

Task	Command	Description
View settings	`Get-CalendarProcessing -Identity "User"`	Shows calendar processing configuration
Enable AutoAccept	`Set-CalendarProcessing -Identity "User" -AutomateProcessing AutoAccept`	Automatically accepts meeting invites
Disable AutoProcessing	`Set-CalendarProcessing -Identity "User" -AutomateProcessing None`	Manual meeting handling
Enable Custom Response	`Set-CalendarProcessing -Identity "User" -AddAdditionalResponse $true -AdditionalResponse "Text"`	Sends custom confirmation messages
Configure Room Mailbox	`Set-CalendarProcessing -Identity "RoomName" -BookingWindowInDays 180`	Restricts booking horizon

🧩 Notes

Use AutoAccept for shared calendars or room mailboxes that should process requests automatically.
Use AutoUpdate if users need to manually confirm requests after tentative acceptance.
Configuration changes may take several minutes to replicate across Exchange Online.

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