This is an (unofficial) Language Tool extension for Thunderbird. This extension makes it possible to query a Language tool server directly from Thunderbird.
The extension may be used with the public Langtool server https://api.languagetoolplus.com/. If you prefer to keep your data locally, run a local instance of the Langtool server and change the Server URL to your localhost instance.
Thunderbird MailExtension. This extension is developed using only the Thunderbird MailExtension API (excluding the Experiments API). This is done to ensure compatibility with future versions of Thunderbird.
First download the latest .xpi of the add-on here, then install it in Thunderbird as usual.
Contributions are more than welcome and encouraged. As mentioned above, the only constraint is only using the Thunderbird MailExtension API (excluding the Experiments API).