I have tried to update the names/email addresses listed in groups; however, while I can see them when I click on people and group name, when it comes time to send an email to them, it gives me two of the same addressees and leaves one off. 

Under manage groups, it tells me that I an delete the name of the group, but the names still stay listed.  Why would I want to delete the group name and not the group itself.  I can click/apply all kinds of things listed, but it doesn't work when I go to do email. 

The more  I work with this new set up, the worse it gets.  I want to know simply how do I delete groups?