I am using the Newsletter plugin and it is really nice.
I need your help for the following issue. I create newsletters with the Responsive Drag and Drop Composer (usually I duplicate a previous and I change some content) and I would like to add a line of css for all my newsletters created by the composer. I don’t want to add this line of css every time I write a newsletter. I tried to use the HTML editor and I added the css there but when I duplicate the newsletter the css is gone.