To enable/disable the spelling checker in Thunderbird
Instant spell checking you can about the Thunderbird settings on or off. This works also, if you are writing a message. This is how it works:
- In the menu bar or in the Compose window click at the top tools > settings > Write > spelling.
- Here you will find the Option "Immediately-enable spell checker" (see image). Remove the hook and put it back, if you want to enable the spelling checker.

Spell check
Practice tip applies to Thunderbird Version 17.0.6. How to use the spelling checker to install, read here.
