In order to create a postcard, please choose the HTML mode for your
message and choose the "Postcard" button from the menu of the editor.
Click on "Define new postcard" link and follow the Postcard Wizard steps.
Once the postcard is defined choose the message where you would like to
insert a postcard to (make sure that you choose HTML as the format).
Click in the body of the message and click on "Postcard" button again.
Choose the postcard from the list available and save your message.