Mailgroup function missing - Any thought to add it back?

I know that you probably had excellent reasons to do it, but I actually miss the possibility to turn some lists into mail groups where group members can discuss. I remember in the past there was an Add on for that, but it was discontinued. We have 5-6 groups of about 10 people that need this, and I really dont want to setup an extra mailgroup solution in parallel to PHP-List.
A) Is it possible to do with PHP-List (i.e. allow users to send an email to a list via email?)
B) If not, any recommendation for a real simple to install and maintain solution / reliable service?

I don’t know about the old plugin. You could update it yourself to make it compatible with current versions of phpList.

Quickml is an extremely simple mailman alternative, but it looks like its no longer maintained either.