I seriously doubt that only one IP of Hetzner sent spam but unfortunately it seems to be pretty common for email providers to soft ban VPS IPs. I don't know ho

I seriously doubt that only one IP of Hetzner sent spam but unfortunately it seems to be pretty common for email providers to soft ban VPS IPs. I don't know how much spam come from cheap hosting services but between the hacked servers and servers rented by spammers it's probably a lot.