Background
Historically, our system has supported booking rooms by creating meetings directly in a room’s calendar and setting the room mailbox as the meeting organizer. While this approach worked in practice, Microsoft’s official guidance states that this is not the recommended method:
Microsoft Exchange resource mailboxes (such as rooms) are designed to receive meeting requests, not to act as the meeting organizer.
When a room is set as the organizer, the built-in Resource Booking Assistant does not process the booking. This bypasses important features such as conflict detection, policy enforcement, and delegate approvals.
Microsoft explicitly advises: “Never set a room mailbox as the organizer of a meeting. Include room mailboxes only in the Attendee or Location fields in the meeting request.”
What Is Changing
To align with Microsoft best practices and ensure long-term reliability of bookings:
Going forward, our software will no longer create meetings with the room mailbox as the organizer.
Instead, we will introduce the ability to set a dedicated service account that will act as the meeting organizer.
The room will then be invited as an attendee, allowing Exchange to apply all booking rules and policies as intended.
Viewing the booking in Planner, either through Planner Web or the Outlook Add-in will be unaffected.
Customers who have Display connected through Planner will also benefit from this update.
Benefits of This Change
Proper conflict handling: Rooms will auto-accept or decline requests based on availability.
Policy compliance: Booking windows, working hours, and delegate approvals will be correctly enforced.
Improved reliability: Prevents calendar inconsistencies and ensures Microsoft-supported booking flows are followed.
Future-proofing: Keeps your environment aligned with Microsoft’s evolving guidance and platform behavior.
Action Required
Create a BRAND NEW user account in your Microsoft Exchange/Admin with a license that enables resource booking (At a minimum this is either a Microsoft 365 Business Basic license or Exchange Online Plan 1 license.)
Note - This account must not have been previously synced with Planner.
Open Planner Web as an Admin and navigate to Administration - Integrations.
Enter the email address of the newly created Service Account into the Account Service Email field.
That's it - all bookings made by Planner Only accounts will now be booked using the Service Account, guaranteeing that Microsoft policies and rules are adhered too, whilst ensuring the actual Organiser in Planner Web continues to be observed.