notifying an author when a comment is posted

I am using the atahualpa theme on a privately hosted blog with multiple authors.
I have tried every internal wordpress setting variation on the “discussion” settings
But no matter what, I get no email notification – nobody does who is part of the site.

I cannot find a plug in that will make sure an author is alerted by email when a comment is made on his/her post.

I tried a few plug ins, none of which worked. I had hopes for this one which I have installed and it also does not work:
“Send Comment Moderation E-mail only to Post Author”

Thanks so much!