When is the problem of emails being sent to contacts removed from groups going to be fixed. It is so frustrating?

I remove people from a group then find out that they have received emails as outlook  is sending emails to people who are no longer in the group. I run a social group and time to time remove people because they request to be removed yet have had a number of complaints that they are still getting emails. I end up having to delete them completely from my contacts and if I still want them as a contact to re add them as a contact.