# Mimestream vs Mozilla Thunderbird

| Attribute | Mimestream | Mozilla Thunderbird |
|---|---|---|
| **Vioscale score** | 63.2 (26% (low)) | 60.1 (27% (low)) |
| activity.commits_last_30d | - | 100 |
| adoption.dependent_repos | - | 0 |
| adoption.github_stars | - | 13,921 |
| deployment.options | `{"cloud":true}` | - |
| description.long | A desktop email application designed for macOS that establishes direct connections to Gmail through its API, combining operating system capabilities with Gmail's functionality. It prioritizes privacy by storing all data and authentication tokens locally on your device rather than routing through intermediary services. | 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. |
| features.capabilities | - | `{"pricing_model":"free_open_source","deployment_model":"local_direct_imap_client","generative_ai_llm_email_drafting":false,"unified_multi_account_inbox_view":true,"universal_imap_smtp_exchange_support":true}` |
| integrations.count | 3 | - |
| integrations.list | `[{"name":"Gmail API"},{"name":"Google Calendar"},{"name":"Apple Calendar"}]` | - |
| language.primary | - | Kotlin |
| license.spdx | - | Apache-2.0 |
| market.availability | `{"primaryMarkets":["US"],"availabilityScope":"global","availableCountries":[],"notAvailableCountries":[]}` | - |
| platform.support | `{"mac":true}` | `{"mac":true,"linux":true,"windows":true}` |
| pricing | `{"type":"subscription","plans":[{"free":false,"name":"Individual","summary":"$4.99/month or $49.99/year with family sharing","features":["Gmail label management with color coding","Server-side filter management","Quick calendar invitation responses","Full Gmail search functionality","Vacation responder configuration","Multiple Gmail account support","Per-account color assignment","Inline mention functionality","macOS UI integration","Family sharing across up to 5 devices"],"components":[{"kind":"fixed","amount":49.99,"period":"year","currency":"USD"},{"kind":"fixed","amount":4.99,"period":"month","currency":"USD"}],"description":"For individual users with family sharing support","contactSales":false},{"free":false,"name":"Team","summary":"Contact sales for custom pricing","features":["All Individual plan features","Centralized billing administration","Team seat management tools"],"minSeats":51,"description":"For organizations with more than 50 seats","contactSales":true}],"summary":"From $4.99/month or $49.99/year. 14-day free trial without credit card.","currency":"USD","freeTier":false,"sourceUrl":"https://mimestream.com/pricing","retrievedAt":"2026-08-20T12:47:29.793Z","freeTrialDays":14,"startingPrice":{"amount":4.99,"period":"month","currency":"USD"},"billingPeriods":["month","year"]}` | `{"type":"free","summary":"Free, open-source. Free forever.","freeTier":true,"sourceUrl":"https://www.thunderbird.net","retrievedAt":"2026-08-21T12:42:28.376Z"}` |
| pricing.free_tier | no | yes |
| pricing.model | commercial | freemium |
| pricing.price_level | low | free |
| pricing.starting_price | `{"amount":4.99,"currency":"USD"}` | - |
| pricing.transparent | yes | yes |
| release.history | - | `[{"url":"https://github.com/thunderbird/thunderbird-android/releases/tag/THUNDERBIRD_22_0","date":"2026-08-11T03:59:18Z","type":"stable","version":"THUNDERBIRD_22_0"},{"url":"https://github.com/thunderbird/thunderbird-android/releases/tag/K9MAIL_22_0","date":"2026-08-11T03:59:18Z","type":"stable","version":"K9MAIL_22_0"},{"url":"https://github.com/thunderbird/thunderbird-android/releases/tag/THUNDERBIRD_23_0b1","date":"2026-08-10T22:13:14Z","type":"prerelease","version":"THUNDERBIRD_23_0b1"},{"url":"https://github.com/thunderbird/thunderbird-android/releases/tag/THUNDERBIRD_21_1","date":"2026-08-03T19:14:04Z","type":"stable","version":"THUNDERBIRD_21_1"},{"url":"https://github.com/thunderbird/thunderbird-android/releases/tag/K9MAIL_21_1","date":"2026-08-03T19:14:10Z","type":"stable","version":"K9MAIL_21_1"},{"url":"https://github.com/thunderbird/thunderbird-android/releases/tag/THUNDERBIRD_22_0b2","date":"2026-07-27T20:45:48Z","type":"prerelease","version":"THUNDERBIRD_22_0b2"},{"url":"https://github.com/thunderbird/thunderbird-android/releases/tag/THUNDERBIRD_21_0","date":"2026-07-20T21:30:00Z","type":"stable","version":"THUNDERBIRD_21_0"},{"url":"https://github.com/thunderbird/thunderbird-android/releases/tag/K9MAIL_21_0","date":"2026-07-20T21:29:55Z","type":"stable","version":"K9MAIL_21_0"},{"url":"https://github.com/thunderbird/thunderbird-android/releases/tag/THUNDERBIRD_22_0b1","date":"2026-07-20T23:20:30Z","type":"prerelease","version":"THUNDERBIRD_22_0b1"},{"url":"https://github.com/thunderbird/thunderbird-android/releases/tag/THUNDERBIRD_20_1","date":"2026-07-06T22:30:54Z","type":"stable","version":"THUNDERBIRD_20_1"},{"url":"https://github.com/thunderbird/thunderbird-android/releases/tag/K9MAIL_20_1","date":"2026-07-06T22:30:53Z","type":"stable","version":"K9MAIL_20_1"},{"url":"https://github.com/thunderbird/thunderbird-android/releases/tag/THUNDERBIRD_21_0b2","date":"2026-06-29T21:12:45Z","type":"prerelease","version":"THUNDERBIRD_21_0b2"},{"url":"https://github.com/thunderbird/thunderbird-android/releases/tag/K9MAIL_20_0","date":"2026-06-23T01:45:10Z","type":"stable","version":"K9MAIL_20_0"},{"url":"https://github.com/thunderbird/thunderbird-android/releases/tag/THUNDERBIRD_20_0","date":"2026-06-23T01:45:03Z","type":"stable","version":"THUNDERBIRD_20_0"},{"url":"https://github.com/thunderbird/thunderbird-android/releases/tag/THUNDERBIRD_21_0b1","date":"2026-06-22T17:24:23Z","type":"prerelease","version":"THUNDERBIRD_21_0b1"},{"url":"https://github.com/thunderbird/thunderbird-android/releases/tag/THUNDERBIRD_19_2","date":"2026-06-04T19:32:37Z","type":"stable","version":"THUNDERBIRD_19_2"},{"url":"https://github.com/thunderbird/thunderbird-android/releases/tag/K9MAIL_19_2","date":"2026-06-04T19:32:32Z","type":"stable","version":"K9MAIL_19_2"},{"url":"https://github.com/thunderbird/thunderbird-android/releases/tag/THUNDERBIRD_20_0b2","date":"2026-06-04T18:27:10Z","type":"prerelease","version":"THUNDERBIRD_20_0b2"},{"url":"https://github.com/thunderbird/thunderbird-android/releases/tag/THUNDERBIRD_19_1","date":"2026-06-03T22:11:56Z","type":"stable","version":"THUNDERBIRD_19_1"},{"url":"https://github.com/thunderbird/thunderbird-android/releases/tag/K9MAIL_19_1","date":"2026-06-03T22:11:55Z","type":"stable","version":"K9MAIL_19_1"}]` |
| security.scorecard | - | 7.2 |
| security.vulnerabilities | - | `{"count":0,"source":"https://advisories.ecosyste.ms/api/v1/advisories?ecosystem=fdroid&package_name=com.fsck.k9&per_page=100","last_12m":0,"max_severity":null}` |

## Capabilities (Email Clients)

| Capability | Mimestream | Mozilla Thunderbird |
|---|:--:|:--:|
| **Capabilities** |  |  |
| 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 |

*Source: Vioscale. Generated 2026-09-01T16:54:00.694Z. "-" = undocumented, not absent.*