Is there a way to keep track of emails sent to users using the Email Field module?

Hi,

I setup a classifieds ad section on my site where authenticated users could post ads. They would input their emails (using the email field module) and anonymous users could email them through that module.

My question is if it is possible to keep track of these emails?

This information is vital because if my users are not receiving any emails then I have to find a new marketing strategy for my site.

Here is my site (if it betters your answer):

http://collegebud.ca/used-books

Many thanks in advance!!