Rated 5 out of 5 stars
I am using ExQuilla for last 4 years and the latest version for Thunderbird 52.x is nearly perfect. Some glitches has only minor impact on overall performance and functionality.
But, as I read here (https://github.com/rkent/exquilla/wiki/Free) the development of ExQuilla ended on support of Thunderbird version 52.x. Am I right? For future Thunderbird major version you do not plan any developments?
If not, I must say, that is really pity, because your AddOn is the only one way with acceptable level of performance and functionality how to use MS Exchange mail server on Linux with Thunderbird client. The only comparable alternative now is Hiri (https://www.hiri.com/), but this email client is very specific and still suffer by many troubles.