FYI, the email@example.com and firstname.lastname@example.org lists are now Mailman 3 lists.
This should not affect posting or receiving messages. The old pipermail archives are still available but will not be updated with new messages. The new archives contain all the old messages. There is a link to the new archive on the old index page and the old listinfo URL redirects to a new info page.
There is a user's guide for MM 3 at https://docs.mailman3.org/en/latest/userguide.html