Subscribe to Newsletter Option

Hi, i was wondering if there is an option to add a checkbox to subscribe commenters to our newsletter as well. we had this implemented as a custom script in our last comments plugin but we would like to switch to wpdiscuz for a few other amazing options you provide with the addons. 

but we found out that the most subscriber we have are coming from this little checkbox where guests can register for the newsletter in one go. is this possible somehow? or am i just missing it?

thanks a lot, cheers arne