[jfil]

Email is probably the least concentrated and gate-kept space on the Internet. You'll be waiting for a very long time until these issues are on regulators' radar.

Proofpoint: * Does very aggressive "bot click" checks when they suspect your email is spam. They'll hit every link in every email, trying to check if the destination page is legit. They'll be rotating IPs and user agents for every hit and probably using the AWS IP range - of your web server blocks this behaviour, then that might be the reason why they penalize your emails. * They will block you based on the behaviour of other mailers that share the same sending IP. If you're not sending from a stable IP that's exclusively yours, then that could be the problem. Think about what other systems live/send email from that IP.

If you send me an email directly from your system (not forwarding an email) then I could take a quick look.