Dear Klaus,
so please check this out. After it loads just click once to hide the initial info display, and then click on the box in the upper right corner, it should open (slide out) a larger version of the plugin. There on the right side you can find an email address, which is at the moment an <a> tag with a href attribute filled out to be a mailto link.
After your last message I tried it out in different browsers, and surprisingly it works fine on Firefox (Quantum 57), but not in Chrome, Chromium or Opera. My OS is Windows 7 x64.
Also here's a youtube clip of what's happening in case the same doesn't happen for you.
And like I said, it didn't happen with version pr13, just with pr14.