Sustainable Substitutes for Big Tech Email Clients

Privacy-friendly Email Client alternatives with public source code.

  • Feasibility: How easily can the average user switch to this substitute? Higher feasibility results in a higher ranking.
  • Editor's Rating: How sustainable is the substitute? The more sustainability attributes it fulfils, the higher it is ranked.
fairemail logo

FairEmail

Fully featured, privacy oriented email client for Android

FairEmail is developed by FairCode B.V., the company of Dutch developer Marcel Bokhorst.
airEmail displays no advertisements, and it contains no analytics and no tracking of any kind, as the developer states explicitly on the project website.
FairEmail is open-source and licensed under GPL-3.0, with the full source code published on GitHub, which permits independent audits and community contributions.
The app blocks tracking pixels, confirms the loading of images and links to prevent tracking, strips unsafe HTML, stores no data on third-party servers and sends no data to the developer except opt-in error reports.
No account with the developer is required, because FairEmail is a client only; you bring your own email address and the app requires no sign-up beyond your existing mailbox credentials.
Almost all features can be used free of charge, with advanced functions such as filter rules, S/MIME support and scheduled sending unlocked through a single one-time in-app purchase rather than a subscription.
FairEmail offers offline storage and offline operations, so messages can be read, searched and composed without an internet connection.
FairEmail is deliberately battery friendly, frugal with data and small at under 30 MB, which reduces both energy and resource consumption compared with the considerably heavier email applications of large providers.
Website
thunderbird logo

Thunderbird

An open-source email and productivity app by Mozilla.

Thunderbird displays no advertisements and does not engage in data mining, as the project states explicitly on its website.
Thunderbird is free and open-source software licensed under the Mozilla Public License 2.0, which allows anyone to inspect, modify and share the code.
Thunderbird stores all data locally on the user's device, does not collect personal data unless the user asks it to, promises never to sell data and includes built-in OpenPGP encryption.
No account with the developer is required, because Thunderbird is a client that connects to the user's existing email accounts, and nothing is gated behind a sign-up.
Thunderbird is free forever and funded primarily by user donations, with the announcement that features deliverable on the user's own device will never be placed behind a paywall.
Thunderbird is highly extensible through its large add-on ecosystem and themes, which allow users to add functionality such as enhanced filtering, additional encryption tools and visual customisation.
As a client that fetches messages to the user's own device, Thunderbird provides full offline access to mail, calendars and contacts without a browser or an internet connection.
Website

How to move away from Big Tech Email Clients

Here's a guide on how to migrate away from Outlook.

Moving away from Outlook begins with the decision of whether to change only the software or also the mailbox provider. The two steps are best considered separately. In most cases the email address can remain unchanged, because a client such as Thunderbird or FairEmail simply connects to the existing mailbox through the open protocols IMAP, POP3 and SMTP; with Microsoft 365 and Exchange accounts this has become considerably easier, since Thunderbird now supports Exchange natively through EWS and the Graph API, which makes it the natural first destination for former Outlook users.

The practical migration then involves installing the new client, letting its automatic account setup establish the connection through OAuth for providers such as Gmail, Microsoft 365 and iCloud, and importing local data. Thunderbird offers built-in import tools that transfer mail, contacts and settings from Outlook, and calendars and address books can be moved through the open standards CalDAV and CardDAV, which keep them synchronised rather than locked in a proprietary file format.

Suggestions and Feedback

If you have suggestions for more alternatives or general feedback, please contact me via email or create an issue over on Codeberg. Suggest Substitute on Codeberg Write an Email