How to download email messages from Yahoo Groups in Debian?

[Gerardo Ballabio <gerardo.ballabio@gmail.com>]

Hello all,
I've learned that Yahoo Groups is going to drop most of its
functionality, in particular it won't host any user contents any more,
including the email archive.

I'm a member of a private group, we have an archive of several
thousands email messages that we don't want to lose.

May I please ask for suggestions on how to mass-download the email
archive from a Debian (Buster) machine?

I'm not subscribed to this list, please keep me Cc:'d.

Thank you very much
Gerardo