Rated 1 out of 5 stars

I installed it but there isn't any button to add !

This review is for a previous version of the add-on (1.1.0). 

Hi dede5e,

the button is not added automatically, but must be added manually to the button bar above the message pane - the one that contains the "reply" and "forward" buttons.

You can add it by right clicking on the toolbar and choosing "Customize".

Regards
Christoph