Text that makes up an email can be viewed in two different modes: the default/standard mode, or the HTML mode. Default mode is recommended when you are editing the text for the Title or Call To Action sections, since they are very simple. HTML mode, which you switch to by clicking on the < / > button (located on top far left of the Full Body box), is recommended for editing the text under the Full Body section.
For example, if you want to remove the dummy text and replace it with text that is from another application, you will want to select the HTML mode icon and then copy-and-paste your text. This way, you can avoid the email having any unwanted HTML tags.
If your email text is very long, and you want to break it up into multiple paragraphs, you can also use HTML mode to modify the text. This can be done by using the HTML paragraph tags (< p > < / p >)
If you also want additional space between the text and the Call To Action button, for example, you can use the HTML break tag. (< br >)
That covers how you can simply edit the body text for an email.