How do I use Apple Mail, without losing privacy?

As I’ve read so far, it seems Apple Mail isn’t really a very bad option compared to ProtonMail. I’ve also read that the security on Apple Mail can be further improved. Something called S/MME (I think ?).

So I’ve decided to use Apple Mail as the new email client. What are the settings I can change to improve my privacy?

Also, am I right in thinking Apple mail is pretty secure? I’m talking about the one that ends with @icloud.com .

There is no extra encryption or security features in that regard, just normal E-Mail.

If you want extra privacy or security features, you’ll have to stick with something like Proton or Tutanota

Note that there’s also an unofficial bridge that works without the premium plans, but you get no support for that by Proton’s support team

I read somewhere that something called S/MMe can be integrated into your apple email and it makes it extra secure.

Any clue about this?

I looked it up. The Wikipedia article on S/MIME links to this quite early on in their (admittedly german) section on E-Mail: EFAIL - Wikipedia

The TL;DR is that it can be exploited/byassed/whatever the correct verb is

S/MIME is different from PGP and requires a certificate. It is only ever used in business (not much anymore) and there’s almost 100% certainty nobody you know uses it or has set it up.

It’s used even less than PGP, and you can’t use it with Proton Mail.