Hey this is Jenny from XYZ Company

I don't FUCKing care where you're FUCKing from.. If I never signed up for your "marketing" mails.

Omg I know. I get so fucking many emails from these kinds of people. Finally went off on a guy who kept emailing me about software for purchase after I told him that I no longer manage software purchases for my company. Told him that if he even replied to my email apologizing I would get his boss involved.

Never heard from him again for some reason...

I once heard a solution for that.
Just buy a own domain and register a 'catch all' at you mailserver. Then use for every registration the email <servicedomain>@yourdomain.com. With this, you can see who selled your data

@d4rkmindz Huh, never thought about that, that might come in handy.