The iCal Sender plugin will automatically send an mail with an ICS attachment whenever teacher/admin creates a course or group calendar event in Moodle. The logic is triggered by listening to following Moodle system event:

• \core\event\calendar_event_created
• \core\event\calendar_event_deleted
• \core\event\calendar_event_updated
• \core\event\user_enrolment_created
• \core\event\user_enrolment_deleted
• \core\event\group_member_added
• \core\event\group_member_removed

Each of these events will cause an email with ICS attachment to be sent to the attendee(s) of the calendar event AND to the creator of the event. This way attendees and organizer can use their calendar application for RSVP'ing, following up who is attending,...