When you select ‘Outlook Appointments’ in Action Reminders, this will create a meeting on the Outlook calendar from the current user. This meeting request is sent from the user to the valid users in the ‘Notify these users’ grid.
A meeting request is generated with Outlook's calendar function. Outlook is designed to require a “Meeting Organizer”, the person who organizes the meeting. Meeting requests are sent to the Outlook users entered in the 'Notify these users' grid on the Action record.
Only the users who have an Outlook profile in the Raiser's Edge will receive the request (BB56788). The “Meeting Organizer” may reference the Outlook meeting to ensure the notification was assigned to someone who can receive it.
Note: How to send an Action reminder to a user's Outlook calendar (BB152012)