If you're exporting the HTML of your email template, we recommend opening the text (.txt) file in a web-enabled editor like Atom, Sublime, Marketo, etc. Opening the file in a web-enabled platform will display a true rendering of the HTML content, including images, which shows the most accurate view of the design.

If you open the file in a text editing program, the images will not be displayed since text-only editors are not able to read images.

Note: You can also copy and paste the HTML code into a testing program such as Litmus that's able to provide complete renderings across various email platforms and devices.