It's a shame that now, where S/MIME is a feature of pretty much every mail app, noone uses it outside of businesses. Opportunistic encryption between mail servers isn't good enough.

We really need a CA that does for mail what Let's encrypt has done for HTTP:

The CA needs to provider proper S/MIME certificates:

- free like Let's Encrypt

- duration of 1 year or longer and

- users generate their own keys