Mailspring vs Thunderbird
Price, platforms and features side by side. The table says where each price was read and when.
Mailspring
Open-source desktop email client for Mac, Windows and Linux
Thunderbird
Free, open-source email app for Windows, macOS, Linux and Android
Where they differ
- Mailspring starts at $8 per month, or $85 per year (Mailspring Pro). Thunderbird is free.
- Only Thunderbird lists an Android app.
- Mailspring also covers templates.
- Thunderbird also covers tasks and calendar.
At a glance
| Mailspring | Thunderbird | |
|---|---|---|
| Pricing | Free plan | Free |
| Starts at | $8 per month, or $85 per year (Mailspring Pro) | Free |
| Free plan | Unlimited accounts, unified inbox, search, mail rules, signatures, templates and themes. A free Mailspring ID adds weekly allowances of Pro features, such as 15 snoozes and 5 send-later messages. | The whole app is free on desktop and Android, with no ads and no paid tier. Development is funded by voluntary donations. |
| Free trial | None listed | None listed |
| macOS | ||
| Windows | ||
| Linux | ||
| Android | ||
| Made by | Foundry376, LLC | MZLA Technologies Corporation |
| Price read from | getmailspring.com | thunderbird.net |
| Checked | Oct 5, 2026 | Oct 5, 2026 |
Who each one suits
Mailspring
- Linux users who want a modern desktop email client
- People who want a free client with unlimited accounts
- Anyone who wants read receipts and link tracking built into email
Thunderbird
- 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
Mailspring
- There is no iOS, Android or web version; the docs say the team is focused on the desktop app.
- Exchange (EWS and ActiveSync) and POP3 are not supported. Microsoft 365 accounts connect over IMAP and SMTP.
- The calendar is a read-only preview for Google accounts; a full calendar is described as coming later.
- No one-time or lifetime license is offered, and Pro does not include premium support.
Thunderbird
- 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.
Key features
Mailspring
- Unified inbox
- One inbox for Gmail, iCloud, Office 365, Fastmail, Outlook.com, Yahoo and other IMAP accounts. The free version puts no limit on the number of accounts.
- Advanced search
- Mailspring indexes mail so that Gmail-style search queries can look through message contents across every connected account.
- Read receipts and link tracking
- Notifies you when a recipient opens a message or clicks a link. A free Mailspring ID can track 5 messages a week of each kind, and Pro is unlimited.
- Send later, snooze and reminders
- Schedule a message, snooze a conversation, or get a reminder when nobody replies. The free allowance is 5 send-later messages, 5 reminders and 15 snoozes a week.
- Translation and grammar check
- Translates drafts and incoming messages and checks grammar in the composer with LanguageTool. Both have weekly caps, which are higher on Pro.
- Open source with direct sync
- The full codebase is published under the MIT license. Mail syncs over IMAP straight from the provider to your machine, not through Mailspring's servers.
Thunderbird
- 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.
Plans
Mailspring
Free$0
Complete email client with unlimited accounts and a unified inbox. Weekly allowances of Pro features: 15 snoozes, 5 send-later messages and 5 tracked messages.
Mailspring Pro$8
per month, or $85 per year
Unlimited snooze, send later, follow-up reminders, read receipts and link tracking, plus higher caps on translation, grammar check and contact profiles.
Thunderbird
Free$0
Every feature of Thunderbird Desktop for Windows, macOS and Linux and of Thunderbird Mobile for Android.
Ways to pay less
Mailspring
- Annual discount
11% off with annual billing
Mailspring Pro is billed monthly at $8 by default. The subscription docs list an annual plan at $85 a year, which they describe as an 11% discount.
- Other savings
Multi-seat discounts for teams
The subscription docs say discounts on multi-seat licenses and annual team plans are available by contacting Foundry376's sales address.
Thunderbird
No public discounts listed.
