Developer reply by Joshua Pack
Rated 3 out of 5 stars
Please restore the most important feature -- tOGGLEcASE -- which was great for times when Caps Lock is on by accident. None of the current options properly fix that.
The only time I need an addon for case is when I have the Caps Lock on by mistake and everything I type is the OPPOSITE CASE OF WHAT i INTENDED.
You can try out the 2.5 version here with tOGGLE cASE: https://addons.mozilla.org/en-US/thunderbird/addon/titlecase-for-thunderbird/versions/
To create your own collections, you must have a Mozilla Add-ons account.