Hi Phil,
You are welcome.
Do not worry, this checked it seems you are OK.
The warning could also be for a comcast policy blocklist address,
you should take that up with your provider of course.
But this is no big thing because it comes with comcast's mail settings through the provider.
So you should not worry about this issue either. Just wanted to make this sure as well.
Stay safe and secure both online and offline,
Damian aka polonus