Rated 5 out of 5 stars
Great extensions like Cardbook, contribute greatly to Thunderbird's productivity element. The author, Philippe Vigneau has been active, consistently improving it, and it shows. It just keeps getting better and better. If you are checking it out, and haven't already added it to your Thunderbird add-ons, I highly recommend that you give it a try.
My thanks, and kind regards to Philippe.