opt in

1. I want to alarm the community, because i got a mail where one guy wanted to receive all his saved data, because now it is his right. And he tried that for simple reason to see if he can sue me, because he literally said in the 2nd mail that he gives me another 48 the response or he will sue...

My site is decades old. Members have opted into my newsletter before there was ever an audit trail. Now with the GDPR I am supposed to be able to prove that my members opted in or face potentially millions in fines. But there is no functionality to prove legacy members have ever given consent...