Before you start
Things you need to know:
You can only change the width of campaigns that originated from pre-made templates in Dotdigital.
You can't change the width of any templates you build or upload yourself outside of EasyEditor.
Change the width of your campaign
In EasyEditor, select the Styles tab in the left side menu and expand the Email width section.
Select either Large, Standard, Small, or enter a custom width.
Custom width must be between 400 and 800 pixels.