Does Gmail still allow password-based login for desktop email clients?

No. Google removed basic authentication for Gmail in 2022. You must use OAuth2 or generate a Google app password (which still requires 2-Step Verification to be enabled on your account).

Which Linux email client works best with Microsoft Exchange or Office 365?

Evolution with the evolution-ews plugin gives the deepest Exchange integration, including calendar and contacts sync. Thunderbird also works well via IMAP/SMTP with OAuth2 if you don't need native EWS calendar sync.

Can I use multiple email accounts in Geary?

Yes, Geary supports multiple accounts. Add each one either through GNOME Online Accounts (for Google) or through Geary's own account wizard for standard IMAP providers.

Is Claws Mail still actively maintained?

Yes. Claws Mail releases updates regularly; version 4.2 was released in 2023. It remains a solid choice for users who want a lightweight, highly configurable client without a heavy GNOME or Mozilla dependency chain.

Should I use the distro package or the Flatpak for Thunderbird?

The Flatpak from Flathub is often more up-to-date and isolates Thunderbird from distro library constraints, which matters for OAuth2 and Wayland notification support. On Ubuntu or Fedora with current releases, the native package is usually fine too.

The Best Email Clients on Linux

Choosing an email client on Linux comes down to what you need: a full personal information manager, a lightweight IMAP reader, or something that handles modern OAuth2 authentication with Gmail or Microsoft 365 without friction. This guide covers the five most practical desktop email clients available today, how to install each one, and how to get OAuth2 working where it matters.

Thunderbird

Mozilla Thunderbird is the most capable general-purpose email client on Linux. It handles IMAP, POP3, SMTP, calendars via the built-in CalDAV client, contacts, RSS feeds, and Matrix chat. Since version 115 ("Supernova"), it ships a completely redesigned UI and native OAuth2 support for Gmail and Office 365 — no third-party workarounds needed.

Install Thunderbird

# Debian / Ubuntu
sudo apt install thunderbird

# Fedora
sudo dnf install thunderbird

# Arch
sudo pacman -S thunderbird

Flatpak is a good alternative if your distro ships an older version:

flatpak install flathub org.mozilla.Thunderbird

OAuth2 with Gmail or Office 365

When you add a Gmail or Outlook.com/Microsoft 365 account, Thunderbird detects the domain automatically and switches the authentication method to OAuth2. A browser window opens for you to log in and grant access. No app passwords, no "less secure apps" toggle. If the auto-detection misses it, go to Account Settings → Server Settings → Authentication method → OAuth2 and set it manually for both incoming and outgoing servers.

Evolution

Evolution is the GNOME project's answer to Microsoft Outlook. It integrates email, calendar (CalDAV, Google Calendar), contacts (CardDAV, LDAP), tasks, and memos in one window. It is the default mail client on many GNOME-based desktops, including RHEL and Fedora Workstation.

Install Evolution

# Debian / Ubuntu
sudo apt install evolution evolution-ews

# Fedora / RHEL
sudo dnf install evolution evolution-ews

# Arch
sudo pacman -S evolution evolution-ews

The evolution-ews plugin is required for Microsoft Exchange and Office 365 (EWS protocol) connectivity. Without it, you can still connect to Office 365 via IMAP/SMTP.

OAuth2 with Google

Evolution uses GNOME Online Accounts (GOA) for Google. Open Settings → Online Accounts → Google, log in, and Evolution automatically picks up mail, calendar, and contacts. For Office 365, add a Microsoft account in GOA the same way and select which services to sync.

Geary

Geary is a clean, conversation-threaded IMAP client built for GNOME. It intentionally omits calendars and contacts — it does one thing and does it well. If you want something fast and distraction-free, Geary is worth a look.

Install Geary

# Debian / Ubuntu
sudo apt install geary

# Fedora
sudo dnf install geary

# Arch (AUR)
yay -S geary

# Flatpak (recommended for latest version)
flatpak install flathub org.gnome.Geary

OAuth2 with Gmail

Like Evolution, Geary delegates Google authentication to GNOME Online Accounts. Add your Google account in GNOME Settings → Online Accounts first, then open Geary and the inbox appears automatically. For non-Google IMAP servers, Geary uses a password; OAuth2 is only handled through GOA.

Claws Mail

Claws Mail is a fast, GTK-based client that has been around since 1999 and is still actively maintained. It is extremely configurable through plugins, uses Maildir or MH folder formats locally, and is a natural fit for power users who manage many accounts or need fine-grained filtering rules. It is lighter on RAM than Thunderbird by a significant margin.

Install Claws Mail

# Debian / Ubuntu
sudo apt install claws-mail claws-mail-plugins

# Fedora
sudo dnf install claws-mail

# Arch
sudo pacman -S claws-mail

OAuth2 with Gmail in Claws Mail

Claws Mail added OAuth2 support in version 4.1.0. To enable it for Gmail, go to Account → Edit Accounts → (select account) → Receive → Authentication → OAuth2. You also need to configure an OAuth2 client ID. The practical path for most users is to generate a Google app password instead (Google Account → Security → App Passwords), use normal password auth in Claws, and keep 2FA active on your Google account. The plugin-based OAuth2 flow works but requires registering your own OAuth2 client in Google Cloud Console, which is a significant extra step not needed with Thunderbird or Evolution.

Comparing the Clients at a Glance

Client	Best For	Calendar/Contacts	Native OAuth2	Approx. RAM (idle)
Thunderbird	Most users, power users	Yes (built-in)	Yes (v115+)	~250 MB
Evolution	GNOME desktops, Exchange users	Yes (full PIM)	Via GOA	~180 MB
Geary	Simple, fast IMAP reading	No	Via GOA	~100 MB
Claws Mail	Power users, low-resource systems	Plugin only	Partial (v4.1+)	~60 MB

Verify Your Setup

After adding an account in any client, confirm the following before calling the setup done:

Send a test message to yourself and verify it arrives in the inbox.
Reply to a received message and confirm it appears in Sent.
Check that new mail notification works — on Wayland, some older client versions have silent-notification bugs; the Flatpak versions are generally more reliable here.
If using OAuth2, log out of the account inside the mail client and re-authenticate to confirm the token refresh flow works without prompting for a password every session.

Troubleshooting

"Authentication failed" after adding a Gmail account

Google disabled basic (password) authentication for Gmail in 2022. If you are not using OAuth2, you must either switch to it or generate an app password at myaccount.google.com/apppasswords. App passwords require 2-Step Verification to be active on your account.

Thunderbird OAuth2 window never opens

This usually means your default browser is not registered correctly. Check with xdg-settings get default-web-browser and make sure a real browser is set. On Wayland compositors, also confirm xdg-open works from the terminal.

Evolution freezes fetching Exchange mail

Ensure evolution-ews is installed and matches the Evolution version. A version mismatch after a partial upgrade is a common cause. Run your package manager's full upgrade, then restart Evolution.

Claws Mail reports SSL/TLS errors on Gmail

Gmail requires TLS on port 993 (IMAP) and 587 (SMTP with STARTTLS) or 465 (SMTP over SSL). In Claws account settings, set SSL/TLS (not STARTTLS) for IMAP on port 993. For outgoing, port 465 with SSL/TLS or port 587 with STARTTLS both work.

Geary shows no accounts on a fresh GNOME install

Geary relies on GNOME Online Accounts or its own account setup wizard for non-Google providers. If GOA accounts are not appearing, open gnome-control-center online-accounts from a terminal and check whether accounts are actually listed there. A missing gnome-online-accounts package on a minimal install is a common culprit.