And what do you actually use? I know the answer is probably self-hosting but maybe there are other solutions for a decent privacy.
I own a custom domain and actually use Tutanota as my host. Self hosting is a nightmare and easy to fuck up, which leads to your emails getting sent to spam or just not receiving. I use custom domain support in Tutanota that costs me $12/yr (2 custom domains) and my domain is $15/yr. Since custom domains stick out like a sore thumb, if I need privacy then I will use AnonAddy to forward to my email with an anonymous forwarder.
Like 99.9% of my emails aren't encrypted but that's not the point. Tutanota removes a lot of the privacy leaks via metadata and has privacy protection measures by default like disabling images from automatically loading. Also it's calendar/contacts/email all rolled into one and everything is e2ee. Not to mention, unlike ProtonMail, they have their own push service that works on DeGoogled Android and can be installed from fdroid.
Oh wow. Maybe I will migrate to Tutanota from Proton then. That price, function, and dedication to privacy sounds quite attractive to me.
I'll just say though, the client is kind of rough and may be missing a lot of features you're used to.
self hosting email is not worth it unless you are Edward Snowden or some whistleblower trying to hide from the biggest government agencies in the world
Anonaddy/Addy.io to create aliases, then PGP encrypt it before forwarding to my Google mailbox.
I also use Proton but considering ditching it in favor of Anonaddy.
Self-hosting email is a major pain in the ass. Good luck avoiding spam filters.
Do not use proton, get yourself a domain and then use something like Migadu to host it for you on that domain. Then you can also use anonaddy to add anonymous addresses where needed.
I use fastmail.com to generate e-mail aliases. Creation is rate limited, but they are virtually unlimited; I have 500+ and counting. Aliases are randomly generated as wordone.wordtwo1234@fastmail.com, so they aren't identifiable to your account.