Mailman private archives

I'd like to set up private archives for Mailman for internal company mailing lists. I've been working on this for a couple of hours and am stumped on two points:

1. How do I make mailman mailing lists in Virtualmin default to private archives instead of public?

2. How do authenticated users access the private archives? I've tried every combination of URL that I could think of, but so far I'm only able to access them when logged in as root.

Thanks.

Andrew Klaassen