Rated 4 out of 5 stars
Happy with this one!
Up to the next one, a button to open a new mail in a Tab instead of a new window!
A little suggestion for enhancement: would it be possible to make the text of the button changeable itself (currently "Addressbook Tab") and the popup text as well when hovering (currently "Addressbook in a new Tab") to your own language (e.g. a fill in field within "Options" where you can apply your own string)? Now I've a English button between other ones in my own language.
Feel free to give me all translation for the addon (options, tooltip, description,..) so I can include them in the package and you will have it by default in your own.
Please use support site to give me such informations.