When your Salesforce events are synced to Outlook, Outlook sees them as newly created events.
Because of this, Outlook will automatically send event invites and event update notifications to the attendees when an event is created or updated by Calendar Sync. This default Outlook behavior cannot be changed and applies whether you're on an Exchange server or an Office 365 server.
Microsoft's technical documentation explains that, "When the event is created, the server sends invitations to all attendees."
Updated Oct. 2022
