The rejection email says it was sent by Microsoft 365

How to tell a Microsoft 365 decline from an Offision rejection when both arrive from the room: Microsoft checks its own rules first and declines directly, and only a meeting it accepts reaches Offision's booking rules.

Updated 2 Sept 2026

Two email messages drawn side by side, both arriving from Room 301, their upper parts dimmed so the eye lands on the bottom line of each. The left one is shaped like an Outlook decline reply — subject Declined, When and Location rows, a bold conflict sentence, the conflicting meeting listed — and a large orange arrow points at its last line, Sent by Microsoft 365, labelled Microsoft 365 rejects. The right one is shaped like an Offision email — Booking rejected title, the reviewer's reason, a View booking button — and the same orange arrow points at its last line, This email is automatically generated by Offision, labelled Offision rejects. Under both, in the arrows' orange: check the last line of the email. — Both rejections arrive from the room, so the header cannot tell them apart — the last line of the message names the system that declined.

When a room is connected to Microsoft 365, two different systems can refuse a booking, and each sends its own email — both arriving from the room’s name. Microsoft always verifies its own rules first; only a meeting it accepts is handed on to Offision’s booking rules. The last line of the email tells you which of the two said no.

Microsoft declined it directly

Most common

The room’s own Microsoft rules refused the meeting — almost always because the slot was already taken. The room mailbox declines straight away, in Microsoft’s wording, listing the conflicting meeting. Offision is never told: the meeting never syncs, so there is no booking record at all — see A meeting booked in Outlook never appears in Offision.

A sequence diagram with three lifelines: the organizer in Outlook, the room mailbox on Microsoft 365, and Offision. The organizer books the room; a note on the room mailbox reads Microsoft's own rules: the slot is taken; the room declines straight away, and an orange arrow marks the line Sent by Microsoft 365 under the reply. The Offision lifeline is never touched — a dashed note on it reads Never told, no record of the meeting. — A conflict is refused by the room itself, before anything reaches Offision — the decline is Microsoft's, and Offision has no record.

Book again at a free time, or in Offision, where the conflict is shown before you confirm.

Offision rejected it after checking

Common

The meeting passed Microsoft’s rules and synced over — then one of Offision’s booking rules failed, or a reviewer turned it down. The rejection you receive carries Offision’s reason, and its last line says Offision generated it. In Offision the booking shows as Booking failed or Booking rejected.

If the room accepted the meeting first and this rejection arrived afterwards, the mailbox is answering before Offision is asked — see How a booking on an Outlook or Google room is validated.

A sequence diagram with the same three lifelines: the organizer in Outlook, the room mailbox on Microsoft 365, and Offision. The organizer books the room; a note reads Microsoft's rules pass, accepted; the meeting syncs over to Offision; a note reads checks the booking rules, one fails; the final arrow runs from Offision back to the organizer, labelled Rejected by Offision with the reason attached, and an orange arrow marks the line This email is automatically generated by Offision under it. — Microsoft's rules pass first — the meeting syncs over, and when a booking rule fails there, the rejection comes from Offision, with its reason.

Fix what the reason names — another time, another room, or ask the reviewer — and book again.