When you start a template from scratch you get two starting elements: a Full width element, and inside that, a Box. These two basic elements are needed to have a template that works well:
The first Full width element
The first Full width element acts as the base of your email, it fills the whole window of the users email client where the email can be read. It is essential for the template to be displayed correctly.
The first Box – a Container
The Box is a container element that usually groups different elements together, titles, texts, images, tables and so on. It is also a tool that can give a different background color for an element or a group of elements.
Furthermore, the box element is the key to the responsivity of your template. It adjusts to the available width and resizes its contents accordingly.
So the first Box that you get in the Full width element has an important role to act as a global container of your whole content.
DO NOT DELETE this Box! If you add more Full width elements to your template later, also be sure to put a Box in it first!
A Box has a default 5px padding, a white background, and a 1px width grey border. This makes sense if you want to add text and image content immediately. In case you have other plans, for example you are building a more complex template with sections, columns, tables and so on, you may want this container Box just to act as a simple container without any styling.
In this case you should set the padding to 0px, clear the background (make the Box transparent), and clear the border by setting it’s width to 0px. See 3.2 Box for details on how to do this.