Umami Email Tracking for Thunderbird

Thunderbird MailExtension that can add opt-in Umami tracking to outgoing HTML messages.

Features

• Compose toolbar popup with per-message toggles for a tracking pixel and tracked links.
• Global defaults in the add-on options page. Defaults are off.
• Umami self-hosted username/password auth with cached token refresh through /api/auth/verify and /api/auth/login.
• Send-time HTML rewriting only. Plain-text message bodies keep original links and never get a pixel.
• Tracking is blocked for plain-text and encrypted compose windows.

Development

npm install
npm run check

Build output is written to dist/. Load that directory as a temporary add-on in Thunderbird.

Umami Routes

The Umami API documents pixel/link creation, but public delivery paths can vary by deployment/version. The options page exposes templates for the public pixel and link URLs:

• Pixel path default: /p/{slug}
• Link path default: /q/{slug}

Adjust those after confirming the public routes on your Umami instance.

Compliance

Tracking email opens and clicks may require notice or consent depending on jurisdiction and recipient relationship. This add-on defaults tracking off and requires explicit global or per-message enablement.