Markov Dictionary Switcher is a Thunderbird extension that will automatically detect the language of the email you are composing and switches the spelling dictionary accordingly.
Markov Dictionary Switcher is an add-on designed to work with Mozilla Thunderbird 2.0 Beta 2 - 3.1.*.
How to Install in Thunderbird:
1. Right-click the link below and choose "Save Link As..." to download and save the file to your hard disk.
2. In Mozilla Thunderbird, open Add-ons from the Tools menu.
3. Click the Install button, and locate/select the file you downloaded and click "OK".
· Mozilla Thunderbird