Email Marketing Design Guidelines for Mobile Devices

Make sure that you’re designing your emails using a grid system. This means that you need to layout your content in vertically and horizontally aligned blocks, with “streets and alleyways” in-between them. This will enable your design to shrink down without losing its integrity. 

Make sure that your text is readable on a mobile device. Think about larger headlines and body size copy and use short, direct calls to action. A

Consider a Single Column Layout.

Always test rendering on mobile devices when creating master templates to ensure they accomplish your readability goals. 

use background colors to visually separate topics instead of horizontal rule

Instead of designing at 600 pixels wide, try reducing your layout to 450, 500 or 525 pixels. 

Make sure your point is conveyed with or without images enabled.

Use a Viewport Meta Tag. Using this piece of code will make email render properly on the iPhone, rather than shrinking the full email. It also makes the email render more quickly.

Source: Click here