6 Best Linux Email Clients to Manage Gmail, Outlook, and IMAP Mail Offline

If you check mail in a browser tab all day, you have probably noticed how quickly the tab gets lost among twenty others, and how little you can do when the connection drops. A desktop email client keeps a local copy of your messages, so you can search and read them offline, manage several accounts from one window, and set up filters that run without depending on a web interface.

The catch is that an email client is also a network-facing program that parses untrusted content all day, so it needs to stay maintained. Providers such as Gmail and Microsoft 365 have also moved away from plain password logins toward OAuth2, which is a sign-in method where you approve access in a browser window instead of giving the app your password.

A client that stopped receiving updates years ago may still open on your desktop, but it can fail to log in or miss security fixes for bugs in the way it handles HTML mail and attachments.

That is why we have written this list that works with the major mail providers, and is available from your distribution’s repositories or from Flathub.

Since the goal is a list you can rely on for the next year or two, we used three simple rules. First, the project must have shipped a release recently, because an email client without security updates is a risk no matter how good its interface is.

Second, it must work with standard IMAP and SMTP mail, and ideally with OAuth2 sign-in for Gmail and Microsoft accounts.

Third, it must be easy to install on the common desktop distributions, either from the official repositories or as a Flatpak.

Set Up Flathub Before You Start

Several clients below are easiest to install as Flatpaks on distributions that don’t package them, such as Rocky Linux, AlmaLinux, and RHEL, so it’s worth setting up the Flathub repository once before working through the list.

On Ubuntu and Debian, Flatpak is not installed by default, so install it with apt first:

sudo apt update
sudo apt install -y flatpak

On Fedora, Rocky Linux, AlmaLinux, and RHEL, install it with dnf (Fedora Workstation already ships it, so the command simply confirms it is present):

sudo dnf install -y flatpak

With Flatpak installed, add the Flathub repository, which is where the desktop apps in this list are published:

flatpak remote-add --if-not-exists flathub https://dl.flathub.org/repo/flathub.flatpakrepo

Log out and log back in once after adding Flathub, because the desktop menu only picks up Flatpak app launchers in a new session.

1. Thunderbird: Best All-Round Email Client for Linux

With Flathub ready, let’s start with the client most Linux users already know. Thunderbird is the free, open-source email client from MZLA Technologies, a subsidiary of the Mozilla Foundation, and it handles mail, calendars, contacts, RSS feeds, and chat in one window.

Thunderbird now ships on two channels. The monthly Release channel gets new features every four weeks, while the ESR (Extended Support Release) channel gets one major update a year and only security and stability fixes in between.

Version 153 became both the monthly and the ESR release in the summer of 2026, and the Thunderbird team’s 2026 roadmap focuses on extending Microsoft Exchange support and refreshing the calendar interface.

Its main features include:

• Multiple accounts with a unified inbox, IMAP, POP3, and OAuth2 sign-in for Gmail and Microsoft accounts.
• Built-in OpenPGP encryption, so you don’t need a separate add-on to sign and encrypt mail.
• Native Microsoft Exchange support through EWS (Exchange Web Services).
• Calendar and address book with CalDAV and CardDAV sync.
• Quick filter toolbar, message archive, attachment reminder, and a large add-on catalogue.

On Ubuntu, Thunderbird is distributed as a Snap, and the thunderbird apt package only installs the Snap for you, so it’s simpler to install the Snap directly:

sudo snap install thunderbird

Since late July 2026, the Snap’s default latest/stable channel follows the monthly releases. If you prefer the slower ESR updates on a work machine, switch to the ESR channel instead:

sudo snap refresh thunderbird --channel=esr/stable

On Debian, Thunderbird comes from the main repository as a regular package:

sudo apt update
sudo apt install -y thunderbird

On Fedora, install it from the official repositories with dnf:

sudo dnf install -y thunderbird

On Rocky Linux, AlmaLinux, RHEL, and other distributions, the Flatpak is the easiest option. Note that the Flathub app ID changed to the all-lowercase org.mozilla.thunderbird in 2026, so older guides that use org.mozilla.Thunderbird point to the previous ID:

flatpak install flathub org.mozilla.thunderbird

Who it suits: almost everyone, and especially users who want one free client that behaves the same on Linux, Windows, and macOS.

2. Betterbird: Thunderbird with Extra Features and Faster Fixes

If you like Thunderbird but wish some long-standing bugs were fixed sooner, the next client on the list builds directly on it. Betterbird is a community-maintained soft fork of Thunderbird, which means it follows Thunderbird’s ESR releases closely and adds its own fixes and features on top.

Because it shares Thunderbird’s foundations, everything from the previous section (accounts, OpenPGP, calendar, add-ons) works the same way. What Betterbird adds are usability improvements that Thunderbird users have asked for over many years, such as better handling of large mailboxes, improvements to search and the message list, and a few interface options that Thunderbird doesn’t offer.

On every Linux distribution, the recommended way to install Betterbird on Linux is the Flatpak from Flathub, which we set up earlier:

flatpak install flathub eu.betterbird.Betterbird

The project also offers a plain tarball download on its website for users who prefer not to use Flatpak. Keep in mind that the tarball doesn’t update itself through your package manager, so you need to download new releases by hand.

Who it suits: Thunderbird users who want a few extra features and quicker bug fixes, and who are happy to follow the ESR release cycle.

3. Evolution: Best for GNOME and Microsoft Exchange

Thunderbird and Betterbird look the same on every desktop, but if you use GNOME, you may prefer a client that blends in with the rest of the desktop. Evolution is GNOME’s personal information manager, combining mail, calendar, contacts, tasks, and memos in one application, and it releases alongside GNOME twice a year.

Evolution’s biggest strength is its integration with work accounts. With the evolution-ews plugin, it connects to Microsoft Exchange and Microsoft 365 through EWS, so you get mail, the shared calendar, and the company address book together.

It also uses GNOME Online Accounts, which means a Google or Microsoft account you added in GNOME Settings shows up in Evolution without signing in again.

Its main features include:

• Mail, calendar, contacts, tasks, and memos in one window.
• Exchange and Microsoft 365 support through the evolution-ews plugin.
• PGP and S/MIME encryption, signatures, and message templates.
• Spam filtering through SpamAssassin or Bogofilter.
• Offline mode, search folders, and mail filters.

On Ubuntu and Debian, install Evolution together with the Exchange plugin, since the plugin is packaged separately:

sudo apt update
sudo apt install -y evolution evolution-ews

On Fedora, the package names are the same:

sudo dnf install -y evolution evolution-ews

On Rocky Linux, AlmaLinux, and RHEL, use the Flatpak, which already includes Exchange support [confirm the Evolution Flatpak bundles EWS support]:

flatpak install flathub org.gnome.Evolution

4. KMail: Best Email Client for KDE Plasma

Just as Evolution belongs to GNOME, KMail is the email client built for KDE Plasma. It is part of the Kontact suite, so it shares contacts and calendars with KOrganizer and KAddressBook, and it is released as part of KDE Gear, KDE’s application bundle that gets a feature release every four months.

KMail stores your accounts and messages through Akonadi, a background service that caches mail, contacts, and calendars for all Kontact applications.

That design makes KMail fast with large mailboxes, but it also means the first install pulls in quite a few KDE libraries, which is worth knowing if you run GNOME or Xfce. The current release line, KDE Gear 26.08, arrived in August 2026, and its 26.08.2 bugfix update in October fixed a crash when sending signed email.

Its main features include:

• IMAP, POP3, SMTP, and Microsoft Exchange (EWS) accounts.
• OpenPGP and S/MIME encryption, with passwords stored in KWallet.
• Spam and virus checking through tools such as SpamAssassin and Bogofilter.
• Powerful filters, saved searches, and HTML and plain text composing.
• Full integration with the other Kontact applications.

On Ubuntu and Debian, install KMail with apt:

sudo apt update
sudo apt install -y kmail

On Fedora, the package is also named kmail:

sudo dnf install -y kmail

On Rocky Linux, AlmaLinux, and RHEL, install it from Flathub instead, since the base repositories don’t carry it:

flatpak install flathub org.kde.kmail2

5. Claws Mail: Best Lightweight Email Client for Linux

The first four clients are full-featured, but they also use a fair amount of memory, which matters on an older laptop or a small virtual desktop. Claws Mail is a lightweight GTK email client and news reader that started life as a fork of Sylpheed and has long since become the actively developed one of the two.

Claws Mail starts quickly, almost everything can be done from the keyboard, and most extra features come as plugins, so you only load what you need. Version 4.4.0 was released in March 2026, and the older 3.x line, which was the last to use GTK2, has reached its end of life, so make sure you’re on a 4.x release. The 4.3.1 update added OAuth2 support for Microsoft 365 GCC High accounts and stronger SCRAM-SHA authentication for IMAP.

Its main features include:

• Multiple accounts with IMAP, POP3, SMTP, and NNTP (newsgroups).
• OAuth2 sign-in for Gmail and Microsoft accounts.
• Plugins for PGP encryption, spam filtering, RSS feeds, and calendar invitations.
• Message filters, colour labels, and user-defined headers.
• Mail stored in the MH format, one file per message, which is easy to back up.

On Ubuntu and Debian, the package name is claws-mail, not claws as some older guides show:

sudo apt update
sudo apt install -y claws-mail

On Fedora, install it with dnf:

sudo dnf install -y claws-mail

On Rocky Linux, AlmaLinux, and RHEL, Claws Mail comes from the EPEL (Extra Packages for Enterprise Linux) repository, so enable EPEL first [VERIFY: confirm claws-mail is available in EPEL 10]:

sudo dnf install -y epel-release
sudo dnf install -y claws-mail

6. Mailspring: Best Modern-Looking Email Client for Linux

At the opposite end from Claws Mail, Mailspring focuses on a polished, modern interface. It is an open-source, cross-platform client built with Electron, the framework that lets developers build desktop apps with web technologies, and its sync engine (mailsync) is written in C++ to keep large inboxes responsive.

Mailspring had a busy 2026. Version 1.17 moved to a newer Electron with native Wayland support and switched the Linux builds to use the system’s SSL and curl libraries, which means security fixes from your distribution now apply to Mailspring as well.

Later 1.17 updates added a calendar day view and agenda view, event editing, one-click unsubscribe, Do Not Disturb detection on Linux, and ARM64 Linux builds.

Its main features include:

• Unified inbox for Gmail, Microsoft 365, Outlook.com, iCloud, Yahoo, and any IMAP/SMTP account.
• Snooze, send later, mail rules, and templates.
• Calendar with CalDAV sync and a contacts view with CardDAV.
• Fast offline search.
• Read receipts and link tracking, plus some features that need a paid Mailspring Pro subscription [confirm the current Free vs Pro feature split].

On Ubuntu, the Snap is the easiest option, and the Snap package has native Wayland support enabled:

sudo snap install mailspring

On Debian, Fedora, and other distributions, download the .deb or .rpm package from the Mailspring releases page on GitHub and install it with your package manager, so that apt or dnf also pulls in the libraries mailsync links against.

On Debian, install the downloaded .deb file with apt:

sudo apt install ./mailspring-*-amd64.deb

On Fedora, install the downloaded .rpm file with dnf:

sudo dnf install ./mailspring-*.x86_64.rpm

If the main window doesn’t appear after you launch Mailspring, which can happen in virtual machines and on systems without GPU acceleration, start it with the X11 backend instead of Wayland:

mailspring --ozone-platform=x11

Tips for Choosing a Linux Email Client

With the list narrowed down to six, the right choice mostly depends on your desktop, your mail provider, and how much your hardware can spare.

If your work mail runs on Microsoft Exchange or Microsoft 365, start with Evolution and its evolution-ews plugin, or with Thunderbird’s built-in Exchange support, both handle the shared calendar and company address book, which a plain IMAP client can’t do.

For personal Gmail or Outlook.com accounts, every client in this list will work, as long as you choose OAuth2 sign-in when you add the account, because Google and Microsoft block plain password logins for most accounts.

On a KDE Plasma desktop, KMail fits in naturally, while on GNOME, Evolution does the same job. On a lightweight desktop such as Xfce or LXQt, or on a machine with limited memory, Claws Mail is the better fit, since both KMail and Evolution pull in many libraries from their desktop environments.

It’s also worth thinking about how you install the client. Distribution packages and Snaps integrate well with your system’s GPG keys and file manager, while Flatpaks run in a sandbox, so features such as attaching files from outside your home directory or using a hardware security key can need extra permissions. When something only fails in the Flatpak version, check the app’s permissions with flatpak info --show-permissions followed by the app ID.

Finally, before switching clients, export or back up your existing mail. If you move from Thunderbird to Betterbird, you can reuse your existing Thunderbird profile, but moving to any other client means adding your accounts again and letting IMAP download your mail, which can take a while on a large mailbox.

If this guide helped you finally pick an email client for your Linux desktop, share it with someone who’s still keeping their inbox open in a browser tab all day.

Conclusion

You now have six actively maintained email clients for the Linux desktop, from the all-round Thunderbird and its fork Betterbird, to the desktop-native Evolution and KMail, the lightweight Claws Mail, and the modern-looking Mailspring.

If you’re setting up an Ubuntu desktop or server and want to get more comfortable with its everyday administration, our Ubuntu Handbook is a good next step.

We’d love to hear which email client you’re using on your Linux desktop and why. Are you sticking with Thunderbird, or have you moved to Betterbird?

Do you connect to Microsoft Exchange through Evolution or Thunderbird? And if your favourite client isn’t on this list, feel free to share it in the comments so we can check it out for the next update.