Rated 5 out of 5 stars

Without this addon, Thunderbird is useless for someone with a GMail Account!

Mozilla (or whatever organisation manages Thunderbird these days) should hire/pay that add-on developper and make this add-on standard, just like they did for Lightning.

Also, they should stop breaking their API, because everytime they do that, they just shrink the amount of add-ons that can be used, and therefore agressively diminish Thunderbird's attractiveness. Version 78 was the nail in the coffin. I have been using it since the mid-2000. Now I switched to another email client. Thunderbird you killed this add-on... and committed suicide!