Forwarding Outlook meetings: what attendees can do and how to stop it

What forwarding does

Microsoft describes forwarding as the way to invite someone to a meeting you did not organise. The recipient’s request appears to come from the meeting organiser, and the organiser receives a notification that you forwarded it. Microsoft specifies that classic Outlook sends this meeting forward notification when the recipient was not originally invited.

For a recurring meeting, Microsoft lets you forward just this one occurrence or the entire series. If you are the organiser, Microsoft’s advice is not to forward your own meeting but to add the person as an attendee and send an update.

Turning forwarding off

As organiser, open Response Options while creating or editing the meeting and clear Allow forwarding. Microsoft says forwarding is allowed by default. Attendees then do not get the forward option. Microsoft limits the organiser’s feature to mailboxes hosted in Microsoft 365 or Exchange Server 2019; check mailbox eligibility as well as the client.

Microsoft lists support for Microsoft 365 users of Outlook for Windows (version 1808 or later on Current Channel, 1902 or later on Semi-Annual Enterprise Channel), Outlook for Mac 16.20 or later, and Outlook on the web for Microsoft 365 and Exchange 2019. It says iOS and Android are not yet supported for this setting.

What still gets through

Microsoft is explicit that even with forwarding prevented, attendees can still reply or reply all to the invitation with an email message, and copy the meeting message or event. When an attendee uses an older client against an older Exchange version or a third-party service, the forward is handled by servers that do not support the feature, so it cannot be prevented.

Treat Allow forwarding as a guard against casual additions, not as access control. Keep sensitive material out of the invitation body and share documents with named people through their own permissions.

An older attendee client is not enough to establish a bypass. Microsoft says Exchange Online, Exchange 2016 and Exchange 2019 can reject a forwarding attempt even if an older client displays the command. Receiving and enforcing a restriction on mobile is also different from offering the organiser’s setting there.

Worked example: a recruitment panel

A fictional hiring manager organises a 60-minute panel with three interviewers and does not want the slot passed around. They create the meeting in Outlook on the web, open Response options and clear Allow forwarding, and keep the candidate’s CV out of the invitation, sharing it with the three interviewers separately.

A fourth colleague later needs to join. One interviewer asks the manager instead of forwarding, and the manager adds the colleague as an attendee and sends an update. That keeps the attendee list in the organiser’s hands and avoids relying on forward notifications.

Check: open the meeting and confirm the attendee list matches the people you invited; compare with any forward notifications you received.

Two special cases

Delegates: Microsoft’s best practice notes that Outlook delegates do not receive meeting forward notifications. If an assistant manages your meetings, check the attendee list rather than expecting a notice.

Shared calendars: Microsoft documented a known issue in which Allow forwarding was missing from Response Options for a meeting on a shared calendar in Outlook for Microsoft 365 versions earlier than Version 2008 Build 13127.20296, fixed in that build; the workaround was to ensure Download Shared folder is checked for the shared mailbox.

If you only want to tell someone about a meeting without inviting them, Microsoft describes dragging the meeting to the Mail icon in classic Outlook to send its details by email; that email does not add the recipient to the meeting.