1. Log into https://lists.illinois.edu.
2. Find the list from the menu of lists.
3. Click "Admin" button next to the list. 
4. Click on "Edit List Config."
5. Click on "Privileges"
6. You'll see the "Who can view list information" setting.
7. Set to your desired visibility
1. restricted to subscribers - silent rejection 
2. anyone from local domain
3. for anyone (open to public)
4. restricted to subscribers
8. Click on "Apply Modifications," at the bottom of the page.
   

The default mail list owner is the "privileged' owner who has write permissions over all list settings.   If you have the "normal" owner role, then you have read permission for most settings and need to contact the lists's 'privileged' owner to change this and other settings.  The privileged owners can also change the permission of a normal owner to privileged if they want to delegate list setting configuration.