I'm a developer and I want to build a Whitelist Only Email service. The idea is changing how emails should work. When you want to message someone on social med

I'm a developer and I want to build a Whitelist Only Email service. The idea is changing how emails should work. When you want to message someone on social media, you have to first add them as a friend, so there is a whitelist-only approach in that regard. Emails should be like that in a way. When you signup for a service, Facebook for example, you go into this email service and whitelist the *.facebook.com domain, so all emails from Facebook will go through your inbox. If your email address ends up in the hands of the bad guys, they can't spam you or send you phishing emails since they are not on your whitelist. Seems like a reasonable solution. I don't know why there is no service like this yet. I'm still doing some market research hence why I stumbled upon this thread. Anyone, please jump in and give me a reason to stop making this email service a reality.