The mail service has to be affordable (around 10 euros per year). Tuta was an option but their plans are somewhat overpriced for me. Anyone using their (Tuta) free plan? How is it?
I have two (paid) Mailbox.org accounts running for the last several years. No problem at all and they include several features that I use on a regular basis like email aliases (not just a + email, but unique emails), disposable email, contacts and calendar that I can easily sync to my phone, etc.
One uses a custom domain name and the other is just a mailbox.org address.
Tuta has a linux desktop app, and their android app is on fdroid and doesn't depend on google play services. Plus they use green energy for their servers
I was tired of proton because their linux vpn app is pretty awful, especially if you use iwd instead of networkmanager like me. Plus they don't even support ipv6. So I was switching to mullvad vpn (which has great linux support and ipv6), and then for the price of just email tuta was cheaper and better on all the things I mentioned without any downsides (to me), so I switched.
It’s sad to me that the answer can’t be “the one you run yourself.”
There’s theoretically no reason why everyone couldn’t run their own mail service who had a domain name. But with spam practices being what they are, self-hosted mail will get binned in most places.
Tuta (free): you can send only like 6 email per day. Otherwise, Tor-friendly. No onion. Support forum on Reddit 😞 Germany.
Posteo.de: 1 €/mo affordable. Nothing fancy. Support via PGP like that’s common sense. Germany. Non-crypto anonymous payments w/ various options (e.g. a prepaid CC): they don’t even ask your name (much less address, cell phone number).
Disroot.org: Free, pop/smtp, community-based, trusted even by the Tails team. w/ onion. Netherlands.
Cock.li: Free, pop/smtp etc. Very Tor-friendly w/ fast onion. It’s good if you think it like disposal. Irresponsible in a way (aka Freedom), but actually 10-year-old & stable. Romania.
Proton (free): bloated, very mixed opinions, yet better than Google. w/ onion (slow). Switzerland. A simple feature like Plain Text view is missing (HTML by default: not serious about privacy).
Don’t worry about e2ee: Even if you get the most expensive plan from e.g. Proton, it’s not e2ee unless both parties use Proton. There is a free, “easy” way to realize true e2e: OpenPGP in Thunderbird (convenient), GnuPG (more secure), etc.
Also, technical score of mailbox.org has been relatively low, not improving: https://internet.nl/mail/mailbox.org/1080449/
(Don’t worry too much about this score, though. It’s only technical; human factors (philosophies, trust, etc.) are more important when it comes to privacy.) This is not a recommendation. DYOR; ultimately, believe your own intuition.
The main downside of Tuta free for me is that you can't create filters for free. The main downside of proton free is that you can't remove their signature...
Your boundaries on cost make it tough, but aside from Tuta you might have a look at mail.ee which has very basic features (no E2EE for example) and a retro web UI, but very high storage limits. They offer free accounts too, and support SMTP/IMAP/POP3. It's Latvian-based so comes with the "100% GDPR compliance" feature if that's of interest.
Zoho.com is another that comes to mind. It's very feature-heavy/slick (you can tell they're attempting to market mainly to small businesses looking for a cheaper Google Workspace), has been around a long time and I've read positive comments from others about the service. It's an Indian company though so you don't get GDPR protections (or similar) as far as I know. The low-end plans are in your price range and I think they still offer a free plan - that's what I have anyway.
I've been a Fastmail customer for decades now and it's exactly what I want a mail service to be, but it's out of your price range and has no free tier.