I've just used this myself for the first time, and here's how I did it.
I had an existing recommendation form that has two universal email functions in it (one for creator, one for recipient), and it also posts into a database the content entered in to the form so the site administrator can see what content is being looked at by site users.
Basically, the captcha coding needs to be added entirely on the form page as far as I am concerned... I might be wrong, but that is the way it is working for me.
Hope that helps.