Ken/all,
? Another possible explanation is that they see the invite from groups.io
? ? ? ? ?===> and treat it as spam.
If you don't read the invite it's easy to reach the "what's this?" state
and follow it with a conditioned response to "just delete" (opt out).??
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?- Jim B.