Deleting a delegate also cancels all their meetings. The system automatically emails the other participants to tell them that this delegate is no longer attending the event. 

If you want to add your own message to the cancellation email, you will need to manually decline each meeting for the attendee before deleting them. This can be done by navigating to the Attendees tab and clicking 'Schedule' to the left of the attendee. Click on each meeting individually, then choose the 'Decline' tab and type in a message.

If a removed attendee wishes to be reinstated on the system with all their meetings intact, you should keep a note of their meetings before deletion. This can easily be done by clicking 'Schedule' next to their name and then choosing 'PDF' in the top left. Either you or the attendee can schedule these meetings again.