It's Sendgrid which is an email blasting or email auto-responder. It's an external tool and if I understand then an API or a piece of code is integrated to Stake to use the registered email to followup their clients. Getting the Sendgrid hack does not mean Stake system was hacked. I have no idea how have you calculated it's a lost over 10 million as hacking their system. Hacking or compromised Sandgrid account is totally a different thing.