Rated 4 out of 5 stars

This is a great little add-on and does just what it promises, but I too, especially on my new HP kbd with the slightly misplaced Caps Lock key, have a tendency to hit Caps Lock mid-sentence, someTIMES MIDWORD, AND THEN FINISH THE SENtence before I look up and see what I've done. Yes, it can usually be repaired with the lowercase option, but if the phrase contains capitalized and/or all-caps words you'd have to select the entire phrase and choose lower case, then select the capitalized words and choose Start Case, and finally choose the all-caps words and choose UPPER CASE . Surely it can't be that much trouble to add a one-step tOGGLE cASE function to TitleCase, especially as most of your reviewers so far seem to be fat-fingered klutzes who all make the same typing error. (no offense, guys)

This review is for a previous version of the add-on (2.0). 

You can try out the 2.5 version here with tOGGLE cASE: https://addons.mozilla.org/en-US/thunderbird/addon/titlecase-for-thunderbird/versions/