Hi Dominic,
The button looks like this:

Clicking "email this page" launches Chrome and opens a blank tab. It doesn't function correctly.
The button has no mention of "No Service". All other buttons are functioning ok but, I have noticed at times that they all can be temperamental from time to time. Usually is less buggy after a restart.
I have backed up the computer and done a fresh install of El Capitan. This should not be the issue. In the past I think I have tried to do a Safari delete and reinstall but that didn't work either.
I'd like to use this service. I was hoping that Apple would have picked this up already.