Fix Meeting Room Subjects (Office 365 - PowerShell)

Solution to a common Office 365 & Exchange Resource Mailbox Issue

In Office 365 & Microsoft Exchange, by default, your resource mailbox won’t show your Meeting Subject. Instead, it replaces this with your organizer’s name. This occurs for privacy reasons, but it’s only the default. Most organizations opt to see meeting subjects instead.

You can read more about this issue in another article, Display shows organizer’s name instead of subject.

If you're looking to fix this with PowerShell from your own machine, here's the full PowerShell script we use to resolve this issue:

Update AddOrganizerToSubject with a Resource Mailbox Credential

The following prompts you for modern authentication (including MFA, if enabled), and allows you to sign in as the Resource Mailbox user directly, to update your resource mailbox calendar processing rules.

Connect-ExchangeOnline

Get-Mailbox -RecipientTypeDetails RoomMailbox | Set-CalendarProcessing -AddOrganizerToSubject $false -DeleteSubject $false -DeleteComments $false -RemovePrivateProperty $false

Get-Mailbox -RecipientTypeDetails RoomMailbox | Get-CalendarProcessing | fl

Read-Host -Prompt "Press Enter to Continue"

You can execute this inline, or just save this as update.ps1 and execute it as an administrator.

It will prompt you to sign in with the email (UPN) and password of the Office 365 resource mailbox you wish to update. You'll need to run this once for each resource mailbox.

Update AddOrganizerToSubject with an Admin Account

The following prompts you for modern authentication (including MFA, if enabled), and allows you to sign in as a Global Admin user, to update your resource mailbox calendar processing rules. Otherwise the same as above.

Connect-ExchangeOnline

$resource = "ResourceMailboxUPN@yourdomain.com";

Get-Mailbox -RecipientTypeDetails RoomMailbox -Identity $resource | Set-CalendarProcessing -AddOrganizerToSubject $false -DeleteSubject $false -DeleteComments $false -RemovePrivateProperty $false

Get-Mailbox -RecipientTypeDetails RoomMailbox -Identity $resource | Get-CalendarProcessing | fl

Read-Host -Prompt "Press Enter to Continue"

You may need to install some additional PowerShell components if you haven't done this before, but you should be prompted to do this the first time you run the script.

Primarily: https://www.powershellgallery.com/packages/ExchangeOnlineManagement/3.1.0

This guide was written and tested with PowerShell 7 on Windows, macOS, and Linux.

This will only affect behavior for future meetings (the meetings already on your calendar aren't going to be affected by this change).

Updated on: 06/02/2023