Good customer contact is of paramount importance for your online store. Your customers can contact you in two ways:
Customers can use their account in your online store to send you a ticket. When they register and login, they will see a menu at the left. By clicking on MY ACCOUNT > My tickets, an overview with previously sent tickets (if any) is shown where they can create a new ticket. Tickets can be called up in the back office through SERVICES > Tickets. Click on a given ticket to read and answer it.
The customer service page of your online store contains a contact form, which customers can use to send a message to the email address specified in the Service field through GENERAL > Settings > General > Company > E-mail addresses in the left menu of the back office.