Proton and Tutanota are both privacy-centric providers who have been around a good amount of time. I'd say both are a good option if you don't want to self-host.

I really enjoy https://mailbox.org, their custom software can be… esoteric at times, but the company and privacy commitments are top notch, and it has PGP built throughout natively, including an option to automatically PGP encrypt all plaintext emails you receive. I joined it originally as a cheaper alternative to Protonmail but these days I really prefer it.

Check out Posteo.

Proton Mail

Proton has a great free tier that may work well for you. I've used them for a while now and it's been great. They have what is probably the most feature-complete private email service out there (unless I'm forgetting something). The main nitpick I have with them is how little they focus on Linux, but that applies more for their other services than email.

I'm a proton unlimited subscriber and it comes with proton vpn and simplelogin premium on top of the 500GB email inbox. I'm very satisfied with it. Signing up for lots of things with email aliases from simplelogin is very convenient and useful for cleaning your inbox of spam

Proton, Tutonota, or Disroot

I'm a Protonmail user (on a paid plan) and like it. The bridge application works decently well on Linux with my desktop mail client. Their 24 month billing plan makes it $3.5/month.

fastmail

I'm surprised no one's posted about Skiff.

I use proton and absolutely love it!

Unless you're a seasoned sysadmin, hosting your own mail server is going to be more trouble that it's worth. It's a lot of work, and when that was a common thing (companies having their own mail servers) usually they had dedicated admin teams (when they bothered hiring more than one admin, that is) to run it. It's a lot of work.

I migrated my domain over to Protonmail a couple of years back, and it's the best money I've spent in a long time.

Not sure how many people know this but there is an i2p mail service too that can work with clearnet and inside i2p. The cleanet is @i2pmail.org and the i2p mail is @mail.i2p .

I have not tried it out in years but just wanted to make others aware in case it fits your use case.

I use Migadu but you need your own domain for that and also it is paid.

I've been using Fastmail for almost a decade now, and extremely satisfied by the service, privacy, features and price.

If you're interested in signing up for it, I have a referral link (the above one isn't it, I'm not that shady) you can use for a 10% discount on your first year.

Good luck with the search.

Have a look at Autistici which includes free alias addresses.

I can recommend StartMail. It's from the same company that develops StartPage

If you want access to some underlying knobs and buttons, but without running your own email server, then Migadu might be interesting.

Been using purelymail.com, they’re pretty cheap and trustworthy imo

I recommend Proton Mail if you just want a simple, no fuss email service. It's free with some paid options, but the paid options are super unecessary and pretty much useless if you just use email to sign up and send support emails. Proton Mail also blocks trackers and cleans links in your emails.