In a course a group is assigned to the course and a learning area. The learning area is assigned to an e-mail course element.
If the group is removed from the course members management, ...
--> NOK: ...the group is still assigned to the learning area, although no longer visible there. So the group members will still get e-mails from the e-mail course element.
--> OK: The group should not be assigned to the learning area anymore and not be visible in the learning area.