LibreELEC is a rather particular Linux distribution, and that matters a great deal when choosing an email client. It is not a general-purpose desktop OS in the usual sense. In practice, LibreELEC is a lean, appliance-style system built around Kodi, with a small read-only base, a very focused package model, and a user experience that assumes you are using the machine primarily as a media centre rather than a daily office workstation. That means the “best” mail manager is not simply the one with the most features it is the one that fits LibreELEC’s lightweight, tightly controlled environment without creating unnecessary complexity.

Because LibreELEC is intentionally minimal, classic distro-friendly formats such as deb, rpm, pacman, snap, and even the usual graphical desktop stacks are often not available in the same way you would expect on Ubuntu, Fedora, Arch, or Debian. In other words, while many of the clients in your list are excellent in their own right, most are not realistic fits for LibreELEC because they rely on a conventional desktop session, a package manager with broad application availability, or a filesystem layout designed for regular app installation.

In this environment, compatibility is only half the story. Usability is the other half. LibreELEC users tend to fall into one of two camps: either they are technically confident and want to do a little extra with the device, or they simply want the system to remain stable and unobtrusive. For both groups, a mail client needs to be light, reliable, and easy to manage without fighting the platform.

Taking all that into account, the three clients that make the most sense to discuss for LibreELEC are Thunderbird, Mailspring, and Tuta Mail. I will also mention Proton Mail because you asked for Proton and Tuta clients to be included whenever compatible, and Proton is relevant conceptually, but on LibreELEC it is usually less practical than the others due to packaging and platform limitations. For completeness, I’ll also note why several other well-known clients are not strong candidates on LibreELEC.

Now, looking at the practicalities in LibreELEC terms, Thunderbird is the strongest general-purpose choice. It has the widest support matrix of the options you listed, and it is the most familiar to users who want IMAP, SMTP, multiple accounts, calendar integration, and a well-understood extension ecosystem. However, there is an important caveat: the fact that Thunderbird offers a tarball, flatpak, snap, deb, rpm, and pacman build does not automatically make it easy to deploy on LibreELEC. LibreELEC is not designed to be a broad application host. If you have added a desktop session or are running a platform variant where Flatpak is available, Thunderbird becomes much more realistic. If not, it is often more theoretical than practical.

Mailspring is the next sensible option, mainly because it provides a polished interface and a low-friction user experience once installed. It is particularly pleasant for people who want a modern mail workflow and do not need the sort of deep enterprise integration that Thunderbird offers. That said, its package choices are narrower: snap, deb, and rpm. On LibreELEC, snap is usually the most awkward of those choices, and the other two are generally irrelevant unless you are operating in a heavily customised environment. In short, Mailspring is attractive, but on LibreELEC it is more “possible” than “natural”.

Tuta Mail is the most interesting option from a security and simplicity standpoint. It ships as AppImage and Flatpak, which are, in principle, the most plausible cross-distro routes for a minimalist operating system. If your LibreELEC build includes Flatpak support or you have created a compatible desktop stack, Tuta can be a neat fit because it is lightweight in concept and easy to reason about operationally. It also makes sense if you want a mail service and client combination with strong privacy defaults. The catch is the same as always with LibreELEC: the distro’s narrow purpose means that even a “portable” format can still be inconvenient if the surrounding desktop plumbing is missing.

Proton Mail deserves mention because it is a reputable privacy-focused choice and is often recommended for Linux desktops. On the packaging side, though, the desktop app is delivered only as deb and rpm, which is not a friendly match for LibreELEC’s usual model. In a standard Debian or Fedora environment, Proton Mail would be a more comfortable recommendation. On LibreELEC, I would treat it as a low-priority option unless you have deliberately turned the device into a more general desktop-capable machine.

By contrast, several of the other clients are simply not worth prioritising here. Evolution and Geary are both good desktop mailers, but they are much happier in GNOME-centric environments than in an appliance-style distro. KMail and Kontact are powerful but even more tied to a full KDE experience. Claws Mail is admirably lightweight, yet still expects a proper Linux desktop installation model. Betterbird is decent if you want a Thunderbird-style workflow, but the packaging is too limited for this use case, and LibreELEC users would gain little over Thunderbird unless they had a very specific reason. aerc, NeoMutt, and Alpine are all excellent terminal-based tools, but LibreELEC is not typically a TUI-friendly platform for day-to-day mail handling unless you have intentionally set up an SSH-based workflow, which is uncommon for this OS.

It is also worth pointing out LibreELEC’s desktop and user profile. Common desktop environments are not really the central story here in fact, most LibreELEC installations do not present a standard GNOME, KDE, or Xfce session at all. That changes what “best” means. On a normal Linux desktop, I would recommend a much broader range of clients. On LibreELEC, I am far more conservative. The mail app should not interfere with media playback, it should not demand a heavy background stack, and ideally it should be deployable without rewriting the system’s intended purpose.

So, if you are serious about mail on LibreELEC, my ranking would be:

• Thunderbird for maximum capability and account flexibility, provided your LibreELEC setup can actually support a desktop app installation method.
• Tuta Mail for privacy-first usage and the best chance of fitting a minimalist packaging model via Flatpak or AppImage.
• Mailspring for a clean, modern interface, but only where its packaging route is practical.

For most users, Thunderbird is the safest functional recommendation, while Tuta Mail is the most conceptually aligned with a constrained system if you already have Flatpak or AppImage support in place. Mailspring is the style pick: attractive and easy to use, but not my first choice on LibreELEC specifically.

If you do decide to install and configure one of these, the exact method depends on how much your LibreELEC installation has been extended beyond the stock media-centre design. The following examples assume you have added a desktop-capable layer and a package/runtime path that can support the chosen application.

1) Thunderbird: best all-rounder, but only if your LibreELEC setup can host it properly

Why choose it: Thunderbird is still the most versatile client here. It handles multiple accounts well, supports IMAP cleanly, and copes better than most with complicated mail setups. If you have a desktop session available, it is usually the most forgiving choice.

Typical install approach: if you are using Flatpak, that is usually cleaner than trying to force a snap-based or distro-package route into a system that was never meant to be a general desktop.

flatpak install flathub org.mozilla.Thunderbird
flatpak run org.mozilla.Thunderbird

Configuration notes: when Thunderbird opens, add your account manually rather than relying entirely on auto-discovery, especially with privacy-oriented providers. For IMAP, use the provider’s documented IMAP and SMTP settings. Enable encryption, check authentication carefully, and avoid leaving “less secure” compatibility options enabled unless the provider specifically requires them. For LibreELEC users, it is sensible to keep the profile simple and avoid heavy extension use unless you genuinely need it.

2) Tuta Mail: the most privacy-conscious fit, assuming Flatpak or AppImage works on your setup

Why choose it: Tuta is a strong option when privacy matters and you want a clean, self-contained client. On a constrained system, that packaging style is helpful because it reduces dependency friction.

Typical install approach: if Flatpak is available, use that first. If not, an AppImage can be more portable, but it still needs the surrounding desktop environment and runtime support to behave properly.

flatpak install flathub com.tuta.Tutanota
flatpak run com.tuta.Tutanota

Configuration notes: log in with your Tuta account and let the client complete initial synchronisation before making judgments about performance. Tuta is built around its own encrypted ecosystem, so it is not a general IMAP client in the same way Thunderbird is. That is fine if you want privacy and simplicity. It is not ideal if you need to aggregate multiple external mailboxes into one interface.

3) Mailspring: worthwhile if you want a polished interface and already have a supported installation path

Why choose it: Mailspring feels modern and approachable, which makes it appealing for users who want something less technical than Thunderbird. It is a decent compromise between usability and features.

Typical install approach: on supported systems, you would normally use the package provided by the vendor. On LibreELEC, that is only sensible if you have deliberately created a setup where snap, deb, or rpm-based installation makes sense. In practice, this is less common than with Thunderbird or Tuta.

# Example only actual method depends on your LibreELEC setup
# Download the package from the vendor site and install it using the appropriate runtime/package path

Configuration notes: connect your account, then verify IMAP sync, SMTP sending, and notification behaviour. Mailspring is best used when you want a straightforward interface and do not need to spend much time tuning plugins or advanced desktop integrations.

In real-world terms, the biggest issue is not the mail client itself but the nature of LibreELEC. A system built primarily for Kodi is not the obvious place to run a full-featured desktop email environment. If email is a secondary convenience, that is fine. If it becomes a daily productivity requirement, it is worth asking whether the device should remain LibreELEC at all, or whether a general-purpose Linux distribution would serve you better.

Finally, on the service side, these are the email providers I would most sensibly recommend for a LibreELEC-adjacent privacy-conscious setup: Proton Mail, Tuta Mail, Fastmail, and Mailfence. Proton Mail and Tuta Mail are the strongest privacy-first choices they make the most sense if you want the client and service to align around security. Fastmail is excellent for reliability, IMAP compatibility, and low-friction day-to-day use, which is valuable if you are pairing it with Thunderbird. Mailfence is also a solid privacy-oriented option with sensible standards support. If your priority is smooth integration with a traditional mail client on a constrained Linux system, Fastmail is often the easiest operational fit. If your priority is end-to-end privacy and you are happy to stay within a more closed ecosystem, Proton Mail or Tuta Mail are the ones to look at first.