I don't think there's a fix here that's free, easy, and avoids you being on the hook.
I'm also a bit fascinated at the potential that you have 100+ people that you are related to but that you're not close to who would opt in to changing their email address onto one that you have ultimate control over.
I'm also a bit fascinated at the potential that you have 100+ people that you are related to but that you're not close to who would opt in to changing their email address onto one that you have ultimate control over.