In the server document, in the "Access server" field we have added a group named LocalDomainUsers that contains :
We also have in the server document, in the field "Not access server", the group "NO ACCESS" that contains various users.
The problem is that users that are present in the group added to the o access field are still accessing the server. We suppose that it is because they are also in the "Access server" section, and it makes sense.
So it seams that the "Access" field has priority on the "No access" field.