Enrico . In alternativa ci sono anche queste strade percorribili:
https://lifehacker.com/how-to-save-and-migrate-your-yahoo-groups-data-before-i-1839172243
http://yahoogroupedia.pbworks.com/w/page/93006447/Chrome%20Application%20To%20Download%20Messages
https://sourceforge.net/projects/grabyahoogroup/
https://www.theverge.com/2019/11/4/20917500/yahoo-group-data-download-how-to