ThunderAI

ThunderAI is an AI email assistant for Thunderbird users who want help writing messages and managing their inbox. You can process email text with a local model or send it to a cloud provider.

• Writing and proofreading: Draft replies, review individual grammar and spelling corrections side by side, or rewrite selected text in a different tone while keeping its HTML formatting.
• Summaries and translations: Summarize one or several emails and translate messages or selected text, with results in a chat window or the message pane.
• Inbox organization: Suggest and assign Thunderbird tags or classify messages using your own criteria; API integrations also support automatic tagging, spam filtering, summaries and inline translations.
• Custom prompts: Apply your own instructions to multiple emails, reuse data placeholders, share prompts through import and export, and choose a separate provider and model for each prompt.
• Events and tasks: Extract calendar events with dates, locations and descriptions, or tasks with due dates, using the required companion add-on ThunderAI Sparks.

ThunderAI runs inside Thunderbird and is open source under GPL-3.0. Ollama processes text fully locally without an API key. It also connects to local or remote OpenAI-compatible servers, including LM Studio; the server you choose determines where processing happens.

Cloud connections send content to ChatGPT, OpenAI, Google Gemini or Claude. The ChatGPT web connection needs an account but no API key. The OpenAI, Gemini and Claude API connections require keys, and automatic email actions require an API integration.