Postorius configuration help

Hi list, I'm looking for a good description for postorius configuration. The Arch wiki is unclear to me, and the mailman documentation points to postorius.org configuration, who then points to another mailman doc providing little info on the actual configuration. Long story short, I'm failing to set up postorius so I can create users and let them log in. It would be highly appreciated if someone proficient in this topic is willing to walk me throuh. I'd then amend the wiki for more clarity. Thanks in advance Georg