I can't get my free email digital certificate.

I can’t get my free Digital Certificate.
Because the page ask me add www.comodogroup.com to save senders list. But I don’t know how to do it.
I can’t find the save senders list in my browsers: ie and firefox.
If somebody can tell me how to find the list. I will be very happy.
If the page has someting wrong. I hope it will be remove quickly.

Email certificate should be collected from the system and browser which have used to apply it. Did it?