The Thunderbird Insider’s Guide
Everything we know about Thunderbird in one document: what it costs, its grades, getting a refund, getting help and what else to look at. Read it here, or keep a copy.
Thunderbird
The Insider’s Guide
Free, open-source email app for Windows, macOS, Linux and Android
Every plan, grade, refund rule and rival among email apps, read from Thunderbird’s own pages.
Made by MZLA Technologies Corporation · checked Oct 5, 2026 · toolgpa.com
Contents
- 01WelcomeWhat it is, who it suits, its grades and the ten things to know first
- 02What it costsEvery plan, the free plan, ways to pay less and how prices have moved
- 03What it doesIts main features, where it runs, what it works with and who makes it
- 04Where it standsIts grades against its category, and whether to keep it or make your own
- 05The alternativesThe tools it is most often weighed against, side by side
- 06Quick answersThe questions people ask about it, each answered in a line or two
- 07About ToolGPAWho made this guide, what else is on the site, and how to cite it
ToolGPA put this guide together from Thunderbird’s own pages, its app-store listings and our grades. Every fact in it is on Thunderbird’s page too, where it is kept up to date. Checked Oct 5, 2026.
Part 01 · Overview
Welcome
What it is, who it suits, its grades and the ten things to know first
3.2
GPA, above 47 of the 51 other email apps we grade
Thunderbird is a free, open-source email app with a calendar, contacts and tasks built in. The desktop version runs on Windows, macOS and Linux and the mobile version on Android, and both handle several accounts separately or in a unified inbox. It is funded by donations rather than ads or data sales, and is developed by MZLA Technologies Corporation, a subsidiary of Mozilla.
To get you started, here are 8 things to know about Thunderbird, taken from its own pages and our grades.
It's an app, not a mailbox, so you bring your own account.
- 1
Best for free, open-source email on any desktop
It runs on Windows, macOS, Linux and Android, but there's no iPhone, iPad or web version.
- 2
It is free
Thunderbird has no paid plan at all. The whole app is free on desktop and Android, with no ads and no paid tier. Development is funded by voluntary donations.
- 3
It runs on 4 platforms
Windows, macOS, Linux and Android.
- 4
Unified inbox for several accounts
Keep every email account in one app and read them separately or together in a unified inbox, on desktop and on Android.
- 5
Calendar, contacts and tasks
The desktop app manages appointments, contacts and tasks alongside email, so scheduling does not need a separate program.
- 6
No ads or data mining
Thunderbird says it does not sell ads in the inbox, collect personal data or train AI on private conversations. It is funded by user donations.
- 7
A 3.2 GPA, above 47 of 51
That is against the other email apps we grade, on value, the free plan, features, ease of use and platforms.
- 8
Keep it
Thunderbird is free, so making your own would save you nothing.
Thunderbird at a glance
- Pricing
- Free
- Free plan
- Yes
- Free trial
- None stated
- Runs on
- macOS, Windows, Linux, Android
- Made by
- MZLA Technologies Corporation, since 2003
- Category
- Email Apps
- Our grade
- 3.2 GPA, very good
The report card
Best for free, open-source email on any desktop
Thunderbird is a free, open-source email app going since 2003, with calendar, contacts and tasks built in and no ads or paid tier. It runs on Windows, macOS, Linux and Android, but there's no iPhone, iPad or web version. It's an app, not a mailbox, so you bring your own account. Thundermail hosting is a separate paid beta behind a waitlist, and support is community forums only.
| Subject | Grade | Comment |
|---|---|---|
| Value for money | A | It's free, where the middle of this category is $8 a month. Every feature of the desktop and Android apps costs $0, with no ads and no paid tier, funded by voluntary donations. Thundermail, the team's own hosting service, is a separate paid subscription and still in beta. |
| Free plan and trial | A | The whole app is free on desktop and Android, with no cap and nothing held back for a paid plan, because there isn't one. The trade-off is support: it's community-based, and Thunderbird says donations don't buy individual technical help. |
| Features | B | Several accounts read separately or in a unified inbox, with calendar, contacts and tasks in the desktop app so scheduling needs no second program, add-ons to extend it, and OpenPGP on Android through OpenKeychain. Nothing in the listing points at a hole in the mail-client job. |
| Ease of use | C | No rating on record, and this is a settings-heavy old hand rather than a tidy modern app: accounts to add, panes and add-ons to arrange, and community forums if you get stuck. A QR code copies your desktop accounts to the Android app. |
| Platforms and integrations | B | Windows, macOS and Linux on the desktop and Android on the phone, so computer and phone are covered and Linux people are included for once. No iPhone or iPad app is listed, there's no web version, and the only integration on record is OpenKeychain. |
An A is worth 4 points, a B 3, a C 2, a D 1 and an F nothing. The GPA is the average of the five.
Who Thunderbird is for
- Fits if you want a free desktop email app with no ads in it
- Works for people who move between Windows, macOS and Linux and want the same app on each
Who it is not for
- Skip it if you're on an iPhone, as Thunderbird Mobile is listed for Android only
- Not for you if you want someone to call when it breaks, because support is community-based
- Too light for anyone who needs an email address as well, since it's a mail app, not a mailbox
- Watch out: Thundermail, the team's own hosting, is a separate paid beta behind a waitlist, $6 a month yearly
- Skip it if you read mail in a browser, as there's no web version
Good to know
Good for
- People who want a free desktop email app without ads
- Linux users, and anyone moving between Windows, macOS and Linux
- Those who prefer open-source software for mail and calendar
Worth knowing
- Thunderbird Mobile is listed for Android only, through Google Play and F-Droid. No iPhone or iPad app is listed.
- It is a mail client, not a mailbox: it connects to accounts hosted elsewhere. The team's own hosting service, Thundermail, is in beta behind a waitlist.
- Thundermail is a separate paid subscription. Its Early Bird Plan is shown at $6 per month, paid annually, with full launch expected in 2026.
- Support is community-based. Thunderbird states that donations do not buy individual technical support.
Part 02 · Pricing
What it costs
Every plan, the free plan, ways to pay less and how prices have moved
Free
No paid plan at all
Thunderbird is free to use.
Thundermail, the team's own hosting service, is a separate paid subscription and still in beta.
Free
$0
Every feature of Thunderbird Desktop for Windows, macOS and Linux and of Thunderbird Mobile for Android.
The free plan
The whole app is free on desktop and Android, with no ads and no paid tier. Development is funded by voluntary donations.
Read from thunderbird.net on Oct 5, 2026.
Part 03 · Features
What it does
Its main features, where it runs, what it works with and who makes it
4
Places it runs: macOS, Windows, Linux and Android
Free, open-source email app for Windows, macOS, Linux and Android. Here is what it does, as its own site describes it, and what it covers: open source, tasks, calendar, email client.
Nothing in the listing points at a hole in the mail-client job.
- Unified inbox for several accounts
- Keep every email account in one app and read them separately or together in a unified inbox, on desktop and on Android.
- Calendar, contacts and tasks
- The desktop app manages appointments, contacts and tasks alongside email, so scheduling does not need a separate program.
- No ads or data mining
- Thunderbird says it does not sell ads in the inbox, collect personal data or train AI on private conversations. It is funded by user donations.
- Open source and extensible
- The code is published under the MPL 2.0 license for anyone to inspect, modify and share, and add-ons extend what the desktop app can do.
- OpenPGP encryption on Android
- Advanced users can send and receive encrypted mail with the OpenPGP standard by pairing Thunderbird Mobile with the free OpenKeychain app.
- Desktop-to-mobile setup
- Desktop users can move their account settings to the Android app by scanning a QR code shown in the desktop app.
Where it runs
- macOS
- Windows
- Linux
- Android
What it works with
- OpenKeychain
Thunderbird is made by MZLA Technologies Corporation, and has been around since 2003.
Part 04 · Standing
Where it stands
Its grades against its category, and whether to keep it or make your own
47/51
Other email apps it is graded above
Thunderbird's GPA of 3.2 is higher than 47 of the 51 other email apps we grade, and level with 3.
It stands best on free plan and trial (A, above 42 of 51) and worst on ease of use (C, above 0).
Thunderbird has no paid plan.
On features, ease of use and platforms it scores 2.7 out of 4, and no tool on the category's chart scores higher without costing more.
Each grade against the category
Every bar is all 52 email apps we grade, cut by the letter each got. Thunderbird’s own letter is outlined.
- AValue for moneyAbove 41 of 51
- AFree plan and trialAbove 42 of 51
- BFeaturesAbove 30 of 51
- CEase of useAbove 0 of 51
- BPlatforms and integrationsAbove 15 of 51
Price against what you get
Each dot is one of 50 email apps. Further left costs less; higher up scores better on features, ease of use and platforms. Thunderbird is the marked dot.
What paid plans start at, a month (each step along is roughly double) →
Keep it, or make your own?
Whether this is something you could build for yourself with an AI app builder, and what you would give up.
Keep it
Thunderbird is free, so making your own would save you nothing.
And it is not the kind of software a weekend replaces. It is one of the better ones too: its GPA of 3.2 is higher than 47 of the 51 other email apps we grade.
What you could make
- Calendar and tasks: an app builder makes these well.
What you could not
- An email client: sending, receiving, threading and searching years of mail.
- Apps for macOS, Windows, Linux and Android that stay in step with each other.
- The depth: we grade its features B, which means it covers the whole job.
What this rests on. Thunderbird’s listing: what it does, where it runs, what it plugs into and what it costs. It is a judgement about the kind of software this is. We have not built a replacement for it, and making your own means looking after it too. How we decide, and every tool’s verdict.
Part 05 · Alternatives
The alternatives
The tools it is most often weighed against, side by side
Microsoft Outlook, eM Client, Mailbird, Apple Mail and Mailspring
The 5 tools Thunderbird is most often weighed against, with where each one differs from it.
- 3.6GPA
Microsoft Outlook
Free plan · from $1.99/mo
Microsoft's email and calendar app for desktop, mobile and web.
- Only Thunderbird lists a Linux app.
- Only Microsoft Outlook lists a web app.
- Only Microsoft Outlook lists an iOS app.
- 2.6GPA
eM Client
Free plan · from $49.95/yr
Desktop email client for Windows and Mac with calendar and chat.
- Only Thunderbird lists a Linux app.
- Only eM Client lists an iOS app.
- Thunderbird is open source, according to its own site.
- 2.2GPA
Mailbird
Free plan · from $34.49/yr
Desktop email client for Windows and Mac with a unified inbox.
- Only Thunderbird lists Linux and Android apps.
- Thunderbird is open source, according to its own site.
- Mailbird can be bought with a one-time purchase.
- 3.0GPA
Apple Mail
Free plan · from $0.99/mo
Free built-in email app for iPhone, iPad and Mac.
- Only Thunderbird lists Windows, Linux and Android apps.
- Only Apple Mail lists a web app.
- Only Apple Mail lists an iOS app.
- 2.4GPA
Mailspring
Free plan · from $8/mo
Open-source desktop email client for Mac, Windows and Linux.
- Only Thunderbird lists an Android app.
- Thunderbird also covers tasks and calendar.
- Mailspring also covers templates.
Part 06 · Questions
Quick answers
The questions people ask about it, each answered in a line or two
11
Questions, each answered in a line or two
The short version of everything above, for when you only need the answer. Each one is told in full in its part of the guide.
Is Thunderbird free?
Yes. Thunderbird is free to use.
How much does Thunderbird cost?
Thunderbird lists one plan. Free: $0.
What platforms does Thunderbird work on?
Thunderbird is available on Windows, macOS, Linux and Android.
Does Thunderbird have an iPhone app?
No iPhone app was listed when its pages were read on Oct 5, 2026. Thunderbird is listed for Windows, macOS, Linux and Android.
Is Thunderbird open source?
Yes. Thunderbird is open source, according to its own site.
What does Thunderbird integrate with?
Thunderbird's listing names OpenKeychain. A listing names up to eight integrations, so it may connect to more.
Who makes Thunderbird?
Thunderbird is made by MZLA Technologies Corporation. It dates from 2003.
What are the alternatives to Thunderbird?
The closest alternatives to Thunderbird in our directory are Microsoft Outlook, eM Client, Mailbird, Apple Mail and Mailspring.
How does Thunderbird compare with other email apps?
Thunderbird's GPA of 3.2 is higher than 47 of the 51 other email apps we grade, and level with 3.
Is Thunderbird good value for money?
ToolGPA grades Thunderbird A for value for money. Thunderbird has no paid plan.
Could I make my own version of Thunderbird?
Thunderbird is free, so making your own would save you nothing. And it is not the kind of software a weekend replaces.
Where this guide comes from
The prices, plans, platforms and features were read from Thunderbird’s own pages on Oct 5, 2026, and the grades were given on Oct 10, 2026. Graded from this listing, whose facts were read from Thunderbird's own pages on 5 October 2026. Also tested with a demo account on 2026-03-10.
Every tool we list gets five grades, A to F, each with its reason, and a GPA that averages them. How each is decided is at toolgpa.com/grades. This guide is ToolGPA’s own work; it is not made, paid for or approved by MZLA Technologies Corporation. Prices change, so check thunderbird.net before you buy.
Part 07 · About
About ToolGPA
Who made this guide, what else is on the site, and how to cite it
3,189
Tools graded, in 94 categories
ToolGPA grades software the way a school report grades a pupil: five subjects, a letter for each with the reason written beside it, and a GPA that averages them. Prices, plans and platforms are read from each maker’s own pages and dated, so you always know how fresh a figure is.
Every grade, review and ranking on ToolGPA is our own judgement. No company can pay for a grade or change one. Every tool on the site has a guide like this one, free to download and pass on. It all lives at toolgpa.com.
3,189
tools graded
94
categories
426
price changes on record
579
apps priced in 12 countries
What else is on toolgpa.com
- Thunderbird, kept up to dateEverything in this guide, with prices and grades as they are todaytoolgpa.com/tools/thunderbird
- How grades are givenThe rules behind every letter and every GPAtoolgpa.com/grades
- Value chartsWhat each tool costs against what it scores, for every categorytoolgpa.com/charts
- CompareAny two tools side by side, plan by plantoolgpa.com/compare
- Price changesEvery price rise and cut on record, each with its sourcetoolgpa.com/price-changes
- Prices by countryWhat apps cost on the App Store in 12 countriestoolgpa.com/prices-by-country
- Pay lessEvery public discount: yearly billing, students, nonprofitstoolgpa.com/save
- Keep or makeWhich tools are worth paying for, and which you could build yourselftoolgpa.com/keep-or-make
Scan for the live page
Prices and grades as they are today
Quoting this guide?
Please name ToolGPA and link to the live page, so readers can check the figures for themselves:
ToolGPA, "Thunderbird: The Insider's Guide", checked Oct 5, 2026. https://toolgpa.com/tools/thunderbird
Know someone choosing between email apps?
Send them this guide: toolgpa.com/tools/thunderbird/guide
ToolGPA elsewhere: youtube.com/@toolgpa
See our other guides
The best-graded email apps after Thunderbird, each with an Insider's Guide of its own.
- Email Apps Insider's GuideEvery one of the 52 email apps we grade, compared
- Microsoft Outlook Insider's GuideMicrosoft's email and calendar app for desktop, mobile and web3.6 GPA
- BlueMail Insider's GuideCross-platform email client with a unified inbox and built-in AI3.2 GPA
- Unroll.Me Insider's GuideFree tool to block or roll up subscription emails3.2 GPA
Choosing software? Every tool graded, every price dated.
Compare tools at toolgpa.com ›Everything in this guide is ToolGPA’s own summary of what Thunderbird’s pages, its app-store listings and public reviews said on the dates shown. Grades are our judgement under the rules at toolgpa.com/grades. Every grade, review and ranking on ToolGPA is our own judgement. No company can pay for a grade or change one. Thunderbird is a trademark of its owner, and this guide is not made, paid for or approved by MZLA Technologies Corporation. Prices and plans change: check thunderbird.net before you buy.