Spark Mail vs Thunderbird: catalog facts
 Spark Mail |  Thunderbird |
|---|
|
Freemium Free for individuals; paid plans add AI features and team tools. |
Free Free forever, funded by donations. |
|
Windows, macOS, Android, iOS |
Windows, macOS, Linux, Android |
- Automatic inbox categorization cuts down on manual sorting
- AI-drafted replies can speed up routine email responses
|
- Unified inbox across every account, or each account kept separate, your choice
- Mail, calendar, contacts and tasks in one application rather than four
|
- AI and team features are gated behind a paid plan
- Some categorization requires manual correction over time
|
- The interface carries a lot of history and can feel dense next to a webmail tab
- Major ESR releases have historically been disruptive for add-ons and settings
|
|
Downloadable app |
Downloadable app |
|
Closed source |
Open source |
|
License not stated |
License: MPL-2.0 |
|
Not stated if an account is needed |
No account needed |
|
Not stated if it works offline |
Works offline |
Checked September 22, 2026 | Checked September 20, 2026 |
Catalog facts only. Anything “not stated” is unconfirmed. Check full listings for details.
Copy comparison link
