This tool is pretty powerful and it checks on social media account too ! When you're using the chrome extension, this tool is seaching (and finding) profesionnal email in seconds with a very high precision.
Sometimes you will not find emails (it happens to me just once for the moment on 10 tries on Linkedin)
The experience is pretty good, the chrome extension will make your life way easier because you just have to click on the button GetEmail to make a powerful research !!