Add-ons
About this Add-on
ReplyAgent - AI email replies for Thunderbird
Draft clear, context‑aware replies in seconds. ReplyAgent adds smart tools to Thunderbird so you can generate a polished reply directly in the compose window—based on the original message’s language, tone, and intent.
What you can do
- Instant smart replies: one‑click Positive, Negative, or Custom reply.
- Language aware: detects the email’s language; you can also switch languages via a custom prompt.
- Handy utilities: summarize a message or translate it before replying.
- Professional tone: outputs clean, well‑structured text you can send as‑is or tweak in place.
Supported AI models
- Google Gemini 2.5 Flash
- Anthropic Claude Sonnet 4
- OpenAI GPT‑5 mini
Setup
- Open Thunderbird → Add‑ons Manager → ReplyAgent → Options.
- Choose a model provider and paste your API key.
- While reading a message, open Message Tools to Summarize or Translate.
- Click Reply to insert the generated draft directly into the compose window.
Privacy and storage
-Your message content is sent to the selected AI provider only when you request a reply, summary, or translation.
-API key and model choice are stored locally in Thunderbird.
Draft clear, context‑aware replies in seconds. ReplyAgent adds smart tools to Thunderbird so you can generate a polished reply directly in the compose window—based on the original message’s language, tone, and intent.
What you can do
- Instant smart replies: one‑click Positive, Negative, or Custom reply.
- Language aware: detects the email’s language; you can also switch languages via a custom prompt.
- Handy utilities: summarize a message or translate it before replying.
- Professional tone: outputs clean, well‑structured text you can send as‑is or tweak in place.
Supported AI models
- Google Gemini 2.5 Flash
- Anthropic Claude Sonnet 4
- OpenAI GPT‑5 mini
Setup
- Open Thunderbird → Add‑ons Manager → ReplyAgent → Options.
- Choose a model provider and paste your API key.
- While reading a message, open Message Tools to Summarize or Translate.
- Click Reply to insert the generated draft directly into the compose window.
Privacy and storage
-Your message content is sent to the selected AI provider only when you request a reply, summary, or translation.
-API key and model choice are stored locally in Thunderbird.
