Alternatives to Thunderbird
Mozilla's open source desktop mail
Thunderbird ranks #12 of 22 in Email clients, with an Alt Score of 76. It is licensed under MPL-2.0, donationware and available on Windows, macOS and Linux. 10 of 11 checklist rows are verified against a public source.
People who manage one or more email accounts and want a free, open-source, privacy-respecting desktop client instead of a commercial webmail service—especially users who value data ownership, customization, and cross-platform (Windows/macOS/Linux) support.
A unified inbox for multiple email accounts alongside built-in calendar and contacts management. Messages can be organized with tags, filters, and folders, and the interface is customizable and extensible through add-ons. Thunderbird is developed as open-source software by Mozilla and does not collect personal data or sell ads based on your inbox contents.
You download and install Thunderbird, then add your existing email account(s) via their login credentials or server settings. From there you read, organize, and send mail, manage your calendar and contacts, and tailor the interface and behavior through settings and add-ons.
Why people leave Thunderbird
Dashed reasons are sourced facts; the rest are opinions. Vendors can dispute.
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Ranked alternatives
Ordered by Alt Score. Click any score to see the breakdown.
Feature comparison
Rows come from the Email clients checklist (15 rows). Human-verified cells only. ? means the value has not been verified.
| Email clients checklist | Thunderbird | eM Client | BlueMail | Canary Mail | The Bat! | Apple Mail |
|---|---|---|---|---|---|---|
| Pricing model | ||||||
| Starts at | ||||||
| License | ||||||
| Platforms | ||||||
| Protocols (IMAP / POP3 / JMAP / Exchange) | ||||||
| Unified inbox | ||||||
| Snooze & send later | ||||||
| Tracking pixel blocking | ||||||
| PGP / encryption support | ||||||
| Conversation view | ||||||
| Offline mode | ||||||
| Rules & filters (local) | ||||||
| Calendar integrated | ||||||
| Multiple identities/aliases | ||||||
| Keyboard-first shortcuts |
Every fact and feature listed for Thunderbird is verified against its own pages. Each alternative is sourced on its own page.
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Platforms Windows, macOS, Linux verified 2026-07-12
Meet the powerful email, calendar, and contacts app for Windows, Linux, and macOS.
https://www.thunderbird.net/en-US/download/ -
License MPL-2.0 verified 2026-07-12
This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0.
https://github.com/thunderbird/thunderbird-desktop/blob/main/mail/moz.build -
Pricing model Donationware verified 2026-07-12
Currently, nearly 100% of Thunderbird’s operating revenue comes from the generous gifts of Thunderbird users.
https://www.thunderbird.net/en-US/donate/ -
Status active verified 2026-07-12
Thunderbird’s latest monthly Release version 145, now officially supports native access via the Exchange Web Services (EWS) protocol.
https://blog.thunderbird.net/2025/11/thunderbird-adds-native-microsoft-exchange-email-support/ -
Protocols (IMAP / POP3 / JMAP / Exchange) Yes verified 2026-07-12
Thunderbird users in Exchange hosted environments often relied on IMAP/POP protocols or third-party extensions. With full native Exchange support for email, Thunderbird now works more seamlessly in Ex
https://blog.thunderbird.net/2025/11/thunderbird-adds-native-microsoft-exchange-email-support/ -
Unified inbox Yes verified 2026-07-12
Manage all accounts separately or in a unified inbox.
https://www.thunderbird.net/en-US/features/ -
Snooze & send later No verified 2026-07-12
This add-on adds true send later functionality to Thunderbird, so you decide when that message gets sent, whether it’s one time or regularly.
https://blog.thunderbird.net/2024/09/maximize-your-day-extend-your-productivity-with-add-ons/ -
PGP / encryption support Yes verified 2026-07-12
it is no longer needed with Thunderbird version 78.2.1 because it enables a new built-in OpenPGP feature.
https://blog.thunderbird.net/2020/09/openpgp-in-thunderbird-78/ -
Conversation view Partial verified 2026-07-12
in contrast to the current threaded view, you have all the messages in a thread
https://blog.thunderbird.net/2025/10/video-conversation-view/ -
Offline mode Yes verified 2026-07-12
Email clients store your emails locally on your device, so you can access and compose emails even without an internet connection.
https://blog.thunderbird.net/2024/09/why-use-a-mail-client-vs-webmail/ -
Rules & filters (local) Yes verified 2026-07-12
A property is a message element or characteristic such as “Subject” or “From”
https://blog.thunderbird.net/2024/11/maximize-your-day-make-important-messages-stand-out/ -
Calendar integrated Yes verified 2026-07-12
Access all your messages, calendars, and contacts in one fast app.
https://www.thunderbird.net/en-US/features/ -
Multiple identities/aliases Yes verified 2026-07-12
The identities API allows to manage the user’s identities (each account can have multiple identities).
https://webextension-api.thunderbird.net/en/mv3/identities.html -
Keyboard-first shortcuts Partial verified 2026-07-12
Once a message comes in, click the number for the tag you want. If you accidentally press the wrong number, don’t worry! Just press ‘0’ to clear whatever label you applied.
https://blog.thunderbird.net/2025/08/maximize-your-day-getting-things-done-with-thunderbird/
FAQ
Yes. eM Client, BlueMail and Canary Mail have a free tier or are fully free. Free-tier limits in the comparison table are verified and dated.
FairEmail, Evolution and Mailspring — every license claim links its source.