Even your email is via SSL unless it’s some horrible provider
Not my understanding! The ability to encrypt emails end-to-end using public-key digital certificates has been around for decades, but hardly anyone uses it! If they did, only the intended recipient (the one who has the corresponding private key) would be able to read the email.
In fact, the European Union recommended that all business emails should be encrypted after the discovery of the ECHELON surveillance program at the turn of the century. The US was spying on business emails.
Digital certificates can also be used to verify the author of a document such as an email, and guarantee it has not been changed in any way. Again, hardly anybody uses this facility!
Secure Socket Layer (SSL) also uses public key infrastructure (digital certificates) to establish encrypted links, usually between a web browser and a web server. Mostly the web server is identified with a digital certificate and the protocol changes from http: to https:. Optionally, the browser can also be uniquely identified with a digital certificate but in my experience this facility is also rarely used.
Email is usually sent over the internet in plain text using the simple mail transport protocol smtp:. Email is not inherently reliable and is open to a wide variety of attacks. Like Ethernet, on its own it does not even guarantee delivery.
Email could be made supremely secure, but hardly anybody bothers with public key digital certificates unless they run a web server. The fundamental issue is that the person who pays for a digital certificate is not the one who benefits. If I want to send you an encrypted email, you have to own the certificate, But if you want to be sure it really came from me, and has not been changed, then I am the one that has to have a certificate..