The default Footer content block uses system merge tags. This includes a physical address and unsubscribe link, which are required by law, as well as a few other important links.
Ideally you are not supposed to make any changes to the Footer block. But, you can edit the text however you want, as long as you retain the required information.
To edit your footer content, follow these steps.
You can make style changes using toolbar. You can edit parameters like Background color, line height, padding etc
Note: For paid accounts you can also remove Spicesend's logo from footer of the newsletters.