can i fork it?
open sourceMPL-2.0Local★ 92active aug 2026

Thunderbird

Private local mail and search without an account tax; AI summaries are somebody else's problem.

Technical Profile & Specs

verified 2026-08-10

Cost
$0 / forever (Open Source)
License
MPL-2.0
Hosting Model
Local (on your machine)
Platforms
desktopone-click install
Installation
Install the official Windows, macOS, or Linux package and add existing mail accounts
Where Your Data Lives
Accounts, settings, indexes, address books, and locally downloaded messages live in the Thunderbird profile; message stores use mbox by default, with Maildir available, while IMAP originals remain at the provider
The Catch / Trade-off
Thunderbird handles private local mail and OpenPGP well, but it has no built-in Canary-style AI summaries or SecureSend service.

Replaces 4 paid apps

up to $49/mo ($588/yr) in subscriptions

Thunderbird FAQ

Common questions

Is Thunderbird free and open source?+

Thunderbird is an open-source tool licensed under MPL-2.0 that runs on local. Private local mail and search without an account tax; AI summaries are somebody else's problem.

What paid software does Thunderbird replace?+

Thunderbird serves as a free replacement for 4 paid SaaS applications: Canary Mail, Fastmail, Mailbird, Superhuman, saving up to $49/month ($588/year) in subscription bills.

How do you install and set up Thunderbird?+

Installation: Install the official Windows, macOS, or Linux package and add existing mail accounts.

What is the catch or trade-off with Thunderbird?+

Thunderbird handles private local mail and OpenPGP well, but it has no built-in Canary-style AI summaries or SecureSend service.