I have a user who is using Comcast email,
and delivery was delayed about 40 hours for some reason.
Yes, this is indeed hapening. Mark talked about it .
Is there a way to tell Comcast not to rate
limit emails from the groups.io servers?
Also according to :
If you're a Comcast user, well I guess
you're not going to see this anytime soon, but if you do, I'd
appreciate it if you could complain to them. I think that helps.