The subject says it all, but I'll repeat it here in case it gets cut off by certain e-mail clients:
groups.io will be down for maintenance this evening, starting at 9PM Pacific Time (4AM Saturday 8/18 UTC), for about two hours.
There has been a banner message to this effect up all day on the web interface, but nothing has come across on traffic on the groups themselves, which leaves e-mail users in the dark.
You can still reply to messages, but all of it will be held in a queue during the maintenance period.
Brian - Windows 10 Home, 64-Bit, Version 1803, Build 17134
The real art of conversation is not only to say the right thing in the right place but to leave unsaid the wrong thing at the tempting moment.
~ Dorothy Nevill