Active Directory, Group Scopes

Active Directory groups can apply to three different scopes: Universal, Global, or Domain Local.

If the group is going to interact with Exchange, the group scope must be set to Universal. Most OU Admins make all groups Universal.

If you use Active Directory Users and Computers (ADUC) to create a group, the group scope defaults to Global.

See Microsoft documentation for further information about AD Group Scopes: