I apologize for any confusion there may have been with singing up for Constant Contact. Constant Contact, an email marketing company that provides tools to help small businesses and non-profits reach their customers. If you are not looking to send out emails, the good news is your account is still in a trial period. These free trials run out in 60 days. After the 60 days have passed you do not have to use your account any further if you do not wish to do so. The account will than no longer be active.
If you're looking to clear out your inbox, I would suggest unsubscribing for emails you no longer want to receive. You can do this by clicking the "Unsubscribe" link in the email's footer.