Password only needed for viewing stuff on the web
If all you want to do is view the archives, then just follow the archives link on the above page. But if you want to change the details of your subscription (or view the subscribers list), you'll need a web based password. To subscribe, you'll need to echo back some responses from the email account that was subscribed - just so the mailing list can verify that you are not subscribing some unsuspecting email address. Once confirmed, then you can post messages from that address and receive all the other messages posted to the list.
