[MM3-users] mailman 3.x upgrade and downgrade

Hi all,

I have a few contradictory questions.

1. How to upgrade the 3.x version?

2. Is it possible to migrate (downgrade) the lists from mailman 3.x to 2.1?

3. If so, what would be the best way to do that?

My mailing list server is running on a CenOS-7x with postgreSQL and the following mailman packages:

django-mailman3 1.3.5 mailman 3.3.2 mailman-hyperkitty 1.1.0 mailman-web 0.0.3 mailmanclient 3.3.2 postorius 1.3.3

We have ~200 lists with more than a decade of history.

thanks

-- Carlos Souza