The Appearance Setting is the general settings for the campaign. The fonts, padding, background color, etc. of the whole email campaign.
To change the general settings of the email such as the width of the email (recommended width is 600 pixels max), the General section is where all the settings are for the whole email. It specifies the background color of the email, font and color of the text of the whole email, link color, line spacing, etc.
The Headings setting is to set the font, font size, font style and color of the header texts (ie. Header H1, Header H2, Header H3)
To change the email's header background, font color, link color, etc., navigate to the Header section and you can apply the settings on this tab.
To change the email's footer settings (ie. background, font color, link color, etc.), go to Footer section.
To have a general setting for the button block, go to the Button section and change the settings of the button (ie. button color, font color, font styles, border radius, etc.)
The Info area setting is for the texts in the email content. Specify the font size and color of the text and links of the email content.
The Adaptability setting will only work in the mobile version of the message in e-mail programs that support adaptivity. Specify how you would like the email to look on mobile.