Which email app can be trusted with my data?

I would say only Mozilla Thunderbird!

The best arguments for a long-term mail storing solution - it keeps your emails and all your mail settings, in a form that is truly portable, so that you can easily move it from computer to computer

I am trusting it with 22 GB of emails (many tens of thousands of emails) organized in many folders.

You can have it connected to many online mail services, so it will sync (and keep an offline copy of your mail) and keep all of them separate. Or, you can configure it to sort all your email in a single place and folder hierarchy.

You can have various types of filters, separately per mail account.

If you are on Android, K-9 Mail is wonderful[0]. But you need to host your emails/calendar/contacts somewhere, for that, I am very happy with Fastmail[1].

[0]: https://k9mail.app

[1]: https://www.fastmail.com

Edited to add that K-9 is an email client (app), but not hosting the emails.

FairEmail. I used to use K9 but FairEmail is far and away the better app. Lots of work ongoing to make it better as well

Host your own mail server, it takes less than a day of work per year to keep things running smoothly and you always know where your data is hosted. Use a smart server for outgoing mail - your IAP most likely mandates this by blocking port 25 outgoing - and configure your MTA correctly to make sure your mail does not get bounced by Google or Microsoft (the most likely culprits to do so in my experience). Use Dovecot as MDA and access your mail from whatever IMAP client you happen to like - Claws mail, Thunderbird, K9, etc. Use Sieve [1] to filter your mail into separate folders, including a spam folder for messages marked as such by SpamAssassin which is used by the MTA to check for such.

What I use:

- MTA: Exim, greylistd + SpamAssassin for spam filtering

- MDA: Dovecot with dovecot-sieve for filtering

- MUA on Linux: mutt, claws-mail

- MUA on Android: K9

- MUA on web: Rainloop as a Nextcloud app, Roundcube standalone

I've been doing this for more than 25 years and never had any significant problems. I get far less spam in my inbox than I see in the Gmail account I registered back when that was a new thing and which I only use for testing purposes. If I am to believe the naysayers on this forum and elsewhere it is impossible to host your own mail but my experience shows they are simply wrong.

Just get a SBC, install a mail stack (MTA + MDA, Sieve, SpamAssassin, some form of greylisting if you want to use that) on it, hook it up to your residential connection, get a domain name and start experimenting.

[1] https://en.wikipedia.org/wiki/Sieve_(mail_filtering_language...

Thunderbird works great for me across different desktop operating systems. It doesn't have the best UI but it is all IMAP and it handles multiple inboxes/calendars (custom domains and an old gmail account) just fine. You can also tweak the settings for each inbox accordingly. I use the default mail app on iPhone.

I've been using Thunderbird almost as long as I can remember, I guess I trust it, but probably blindly.

Another interesting question is, which email backend can you trust? It's literally your post-box, can you really trust that to be anywhere except on a physical machine in your own home?

I think ProtonMail is as safe as it gets without setting up your own mail server. Their software is open source and they regularly perform security audits.

Anything that uses standard mbox or maildir formats should be fine. I have mail going back across multiple operating systems and mailer programs since 1995; it has imported without a problem each time.

From 1986-1994 I used a bizarro lash-up to get email through UUCP, which imported the messages into a DOS BBS program to use as a reader. (I said it was bizarro...) The incoming mail was in standard UUCP format, and could have been imported into any common Unix mail program of the day, and thence propagated into the future. Fortunately the BBS mail datasets were plain text, and I can still read them, even if they're not as convenient as a normal mail reader. For that matter, I can still read them running the original 1986 BBS software in DOSEMU.

If you are on macOS/iOS the built in apps for email/contacts/calendar/notes are really nice. Your data stays on your device, and no third party servers will be involved.

Surprised to not to see Sylpheed here.

It's not the best MUA there, but for the last.. five? Years it was the best one for me.

No HTML mails, no JavaScript things, no pixel trackers. Sure, I don't communicate with a living people often, and the portable version I use doesn't integrate good in the OS nor it stores the password in a secure way (it's plain text there, be warned), but it serves the purpose communicating with people and ocassionly searching my emails for something.

Overall, 8/10 for the MUA experience.

If you’re on Mac or iOS, the built-in mail client is not too bad. Alternatively there’s MailMate for Mac, Evolution for Linux and Thunderbird which is cross-platform.

An SMTP relay could make a copy of your emails before they even reach your inbox. Lack of TLS support on the sender side and the context goes clear text through relays. Encryption remains the best way to guarantee against eavesdropping.

Does it absolutely have to be a 3rd party service? How about: https://thehelm.com?

First off, I’ll be a bit of an ass. You seem to be looking for a free option that meets your criteria. You’re on HN, you know that isn’t going to happen.

Second, split desktop and server. You can use Outlook or Thunderbird or pine from the CLI, depending upon what you care about.

Third, let’s face the server problem. There are plenty of options for self hosting all of these [1]. The trade off is that you’re going to spend WAY more time and money in maintaining it.

1: https://github.com/awesome-selfhosted/awesome-selfhosted

Have a hard rule: no non-free software.

I've used Alpine for email and Emacs's Calendar for calendar.

Tutanota.

I just kept using Gmail, too much work imo. I can't bother to migrate everything.