Received from Shal Farley at 11/10/2018 03:11 AM UTC:
Jim,
The most effective solution to Gio mass bouncing problems is direct contact with the ISPs doing the bouncing by someone responsible at Gio.
It isn't as if Mark doesn't already know any of what you've said.
I don't recall any mention in this instance, but in prior incidents Mark has mentioned his contact, or attempt at contact, with various email services. Not that all of them are particularly receptive to such contact.
Yes, there are a few rogue ISPs who don't care, but the major providers of Internet access to the masses don't fall into that category. If the right people are reached the blocks should get lifted.
Jim H