The more obvious link from the front page - "maiing lists" in the mailing lists tile - goes to lists.postgresql.org, which isn't the best entry point, *especially* if you're not already logged in to a community account.
Making the first link in the mailing lists tile go to /list/ would be an easy improvement, I think. A page that has the list names and descriptions, along with "archive" and "subscribe" buttons would be better still (that page may exist, but if it does I can't find it).
I actually have a patch in that should be submitted later today this very issue.