Please note that regular accounts have access to email logs of the last 7 days of sending and the PRO and grandfathered accounts can see the last 35 days of logs.
From your Reports Screen, select your Email Logs. Use the search tool to find all of the emails sent to a specific contact. Type in the email address of the contact and hit "Enter". If the address is found, you may select it to view all of the emails sent to that address in the last 35 days.