I'm not seeing this massive email but no one can edit their notification settings. When they do they see the same error you show above.
Thank you
I just looked at mail jet for the last 7 days. It's showing 3 to 4000 a day starting on the 7th. that's way to much for my site.
Me too, I am using mailjet too and had to disable it because the cost went sky high. That’s how I noticed what was happening.
