Excellent Rated 5 out of 5 stars

Excellent! This is a most useful add-on. I would like to ask for the option to highlight INCOMING messages too, which -to me at least- would be also very useful. Wonder if that's possible?

This review is for a previous version of the add-on (0.6.2). 

Thanks for the feedback

Everything is possible, as long as I have the time. However, for now, I need to fix some bugs first.
It's already very difficult to find complete and up to date documentation to develop thunderbird extensions, and it's take too much time to do simple things. Once I'll be entirely satisfied with the quality of the extension, I'll add this function.
Feel free to help, however, the code is on github ;-)