Linking emails on the Potential and Contact Pages

Linking emails on the Potential and Contact Pages

I currently have one contact linked to each potential. I would like to see a record of the emails I send under each potential. So far, I am able to email each contact from the Potential page, but I don't see a record of the email that is sent nor the reply email on the Potential page. I do, however, see the email only under the contact page. How can I link emails so that I can view them under the Potential page?