Right in the compose window
The “Fix the text” action is added to the context menu of Thunderbird’s compose window.
Mozilla Thunderbird
AI spell checker for your emails in Thunderbird
Fix your email text without leaving Thunderbird. In the compose window, select your text, right-click, and it’s replaced with a corrected, formatted version.
Two versions available — pick your interface language.
Correctify for Thunderbird adds a right-click “Fix the text” action in the email compose window. The selected text is corrected then replaced in place, with its formatting (bold, lists, paragraphs) preserved. Two builds are available: a French interface and an English one.
What Correctify does
Formatting preserved
Bold, italic, underline, lists and paragraphs are kept. Text comes back clean, ready to send.
FR and EN builds
One build with a French interface, another with an English one. Each with its own API key.
Multi-provider
Google Gemini, OpenAI or Anthropic, based on the key set in the options.
Set up in 2 minutes
- 1
Install the add-on
Add Correctify (FR or EN) to Thunderbird from the add-ons site.
- 2
Open the options
Add-ons → Correctify → Options, to enter your API key.
- 3
Fix your emails
In the compose window, select text, right-click → “Fix the text”.
Pick your AI
Correctify detects the provider from your key: a Google key (AIza…) calls Gemini, an OpenAI key (sk-…) calls ChatGPT, and an Anthropic key (sk-ant-…) calls Claude. You stay in control of the service and the cost.
Privacy
No intermediate server, no data collection. Your key and your text only go to the provider you chose.
Learn moreFrequently asked questions
What’s the difference between the FR and EN builds?
The interface and labels differ (French or English), and each build stores its own API key. The correction itself always follows the text’s language.
Is my email formatting kept?
Yes. Correctify keeps the essential formatting tags (bold, italic, underline, lists, paragraphs) when replacing the text.
Which Thunderbird version is required?
Thunderbird 91 or newer.
