All,

Over the past years (as early as 2014, I think), there have been many times we've seen the need to move off Mailman2: it's implemented in python2.7 which has long seen the end of its life.

The alternative has always been Mailman3, which is the technological successor of Mailman3, but a complete rewrite. As early as its initial release in 2015, I've been eyeballing moving to it.

Back then, there was no migration path from 2 to 3, but it was on the roadmap, which made the choice to move or stay easy: wait for the release which makes it possible.

A lot of time has gone by since. The situation gradually worsened, because the migration to Mailman3 became a blocker to upgrade the operating system on common-lisp.net: python2.7 was phased out, which means the mailman2 list software wouldn't run on it anymore (that is, without significant maintenance burden to maintain our own python2.7 install).

Long story short: Yesterday, I installed the containers which allow us to run mailman3 in an isolated environment. There's a lot of tweaking to be done, but I've been able to configure mailman3 to run alongside of mailman2, which is a good start.

As of right now, I've started migrating to mailman3, which I'm doing in steps:

- basic validations

- archives of defunct lists

- active mailman2 lists with configuration and archives

Before going the route of migrating active lists, I may do an assessment of the activity of mailing lists, asking owners of mailing lists which have gone without activity for 5 years, whether there's still an active interest.

Regards,