The Valencian Spellchecker (compact) is a Thunderbird add-on that checks spellings according to the official Valencian language formulated and regulated by the RACV.
If you're interested in installing the extension to your Thunderbird account, here are the steps you should follow:
1. Right-click the link provided below and select "Save Link As..." to download and save the extension file to your device.
2. Launch Mozilla Thunderbird and navigate to Add-ons using the Tools menu.
3. Click on the Install button and locate the extension file you saved previously. Select "OK" to start installation.
Overall, the Valencian Spellchecker (compact) extension could be a beneficial tool for Thunderbird users looking to improve their Valencian writing expertise.