Earlier quoted context omitted.
To have secure email I think html /css should be dropped from email support and the inbox should work on an invite only basis. Basically you should pre-authorize the senders just like you add someone as friend on a social network.
> Basically you should pre-authorize the senders This is kinda what 'masked email' services like Fastmail's – of which I am a delighted customer – do. Until you've known the comfort of creating an address; giving it to a service; deciding that you want to end your relationship with them; just deleting that address, without changing your mailbox or infrastructure or archives or anything else … it's kinda life changing…
That's why I bought my email domain and use @hnrobert42.com. It helps to use a password manager.
I get a lot of convincing emails to linkedin@hnrobert42.com. As well as zynga, wework, etc.