Spatial Navigation allows you to navigate between links with your arrow keys.
Navigate between links using the arrow keys in addition to the tab key.
· Thunderbird 1.0+ - 1.0+ Linux, Windows
How to Install in Thunderbird:
1. Right-Click the link above and choose "Save Link As..." to Download and save the file to your hard disk.
2. In Mozilla Thunderbird, open the extension manager (Tools Menu/Extensions)
3. Click the Install button, and locate/select the file you downloaded and click "OK"