> I believe you could pay to get a proper certificate from a trusted CA for your email address to use S/MIME - I have no idea if any CA still does this or how m

> I believe you could pay to get a proper certificate from a trusted CA for your email address to use S/MIME - I have no idea if any CA still does this or how many people do so. There are a handful of CAs that offer S/MIME certificates, not that obscure of a service really. Actalis is the only one doing it for free though. It is a bit cumbersome but it's rather well-supported (gmail, apple mail, outlook, thunderbird etc.). Hopefully things get simpler now that the CA/B forum S/MIME workgroup is working on clear baseline requirements (so the ecosystem is still moving forward). Something like a mailbox-validated "Let's Encrypt" would be doable and I hope something like that would appear at some point.