Another thing which bears mentioning is that the new mailing list driver
rejects HTML emails, and your mail client should be configured
accordingly. This would be a good time to brush up on mailing list
etiquette in general:
https://man.sr.ht/lists.sr.ht/etiquette.md
I apologise for the inconvenience if you have to adjust your MUA
configuration - but a mailing list without HTML is a happier mailing
list for everyone in the long run.