What is Mozilla Thunderbird?
Thunderbird consolidates email, calendars, and contacts from multiple accounts into one interface. It runs on Windows, Mac, and Linux, is funded by user donations, and prioritizes privacy by never collecting personal data or serving advertisements.
Mozilla Thunderbird pricing
We don't have Mozilla Thunderbird's full plan breakdown yet (its pricing page resisted automated reading). Here's what we could confirm. Always check live pricing for exact numbers.
Free, open-source. Free forever.
What Mozilla Thunderbird does
The capabilities that matter for email clients, normalised so it lines up with every alternative. “-” means we haven't confirmed it, not that it's missing.
- Deployment model
- Local direct imap client
- Universal imap smtp exchange support
- ✓
- Keyboard shortcut only navigation speed
- -
- Split inbox AI auto categorization
- -
- Read receipts and open tracking
- -
- Snooze and scheduled send later
- -
- Generative AI LLM email drafting
- ✗
- Conversational chat layout view
- -
- Unified multi account inbox view
- ✓
- Pgp end to end encryption support
- -
- SOC2 type ii
- -
- ISO 27001
- -
- Pricing model
- Free open source
Platform & deployment
Independently observed- macOS
- Linux
- Windows
Security & compliance
Known vulnerabilities: 0 (0 in the last 12 months) sourcea count reflects scale & disclosure, not quality
Mozilla Thunderbird alternatives
Other email clients we track, ranked by the same independent score.
- SpikeEmail reimagined as AI-assisted team collaboration combining messaging, documents, and calls in one workspacelow · 25%
- SuperhumanAI-powered productivity suite that integrates with your existing apps and workflowsmedium · 61%
- Spark MailMulti-platform email client with intelligent organization and AI-powered writing assistancelow · 43%
- Mailspringlow · 29%
- MimestreamIntegrated Gmail management tool built as a native macOS applicationlow · 26%
- Canary MailA cross-platform email client with built-in encryption, AI assistance, and privacy protections.low · 43%
Compare Mozilla Thunderbird
Side by side against other email clients, attribute by attribute, with a source on every value.
The Vioscale score: one lens on the evidence
Not user reviews and not a paid placement: a confidence-weighted blend of the independent signals below (adoption, activity, security posture, and more), which you can sort and re-weight yourself. Vendors can correct their listing but can never move their rank, and stars are weighted low as a vanity metric. It is one way to read the evidence for Mozilla Thunderbird, not the verdict.
| Signal | Score | Weight | Contribution | Evidence |
|---|---|---|---|---|
| Pricing transparency | 80 | 0.08 | 6.7 | ✓ |
| Development activity | 63 | 0.09 | 5.9 | ✓ |
| Price level | 100 | 0.05 | 5.2 | ✓ |
| Capabilities | 46 | 0.08 | 3.8 | ✓ |
| Security score | 72 | 0.04 | 3.0 | ✓ |
| Stars | 78 | 0.03 | 2.0 | ✓ |
| Reliability | 0 | 0.07 | 0.0 | - |
| Integrations | 0 | 0.09 | 0.0 | - |
| Dependent projects | 0 | 0.06 | 0.0 | ✓ |
| Release cadence | 0 | 0.05 | 0.0 | - |
| Security posture | 0 | 0.07 | 0.0 | - |
| Package downloads | 0 | 0.14 | 0.0 | - |
| Developer Q&A activity | 0 | 0.06 | 0.0 | - |
Computed . Re-weight it by intent, or see the full method.
All data & sourcesshow ↓
Every value we hold, with its source, retrieval date, and confidence. This is the evidence behind the score: don't trust it, verify it.
Activity
| Attribute | Value | Evidence |
|---|---|---|
| Commits last 30d | 100 | mediumsource · 2026-08-26 · 65% |
Adoption
Features
| Attribute | Value | Evidence |
|---|---|---|
| Capabilities | Pricing model: free_open_source · Deployment model: local_direct_imap_client · Generative ai llm email drafting: No · Unified multi account inbox view: Yes · Universal imap smtp exchange support: Yes | mediumsource · 2026-08-21 · 60% |
Language
| Attribute | Value | Evidence |
|---|---|---|
| Primary | Kotlin | highsource · 2026-08-26 · 90% |
License
| Attribute | Value | Evidence |
|---|---|---|
| Spdx | Apache-2.0 | highsource · 2026-08-26 · 95% |
Pricing
Release
| Attribute | Value | Evidence |
|---|---|---|
| History | 20 items | mediumsource · 2026-08-26 · 70% |