The mailing list appears to be broken
The web service provider migrated this site (and a few others) to a new server. It did cause me a bit of alarm at first, as all the notifications were hiding in my SPAM folder and the sudden rash of certificate errors and new server names associated with them started hitting me all at once. I thought I had been hijacked.
As far as I can tell, only the mailing list is broken, and I hope that I’ll get a chance to get that corrected over the next few days.