HTML Design and Rendering Tactics for Improved Email Deliverability and Increased Response

They already know that there are many factors, such as reputation, list hygiene, bounce rates, and server configuration that impact they email deliverability. But did they know that the way emails are designed can also affect it as most spam filters include design-based rules? If they are not following best practices for HTML design and rendering, they messages could look like spam to the ISPs and, therefore, may be delivered to the recipients junk mail folders or be blocked all together. Even if the messages make it to the inbox they will be ignored, deleted, or reported as spam if they do not render correctly or if they contain broken images and links.