Target mobile devices with the @media query The @media query will provide targeted CSS style sheets that are triggered when a device’s capabilities match specific criteria. It will allow you to adjust widths, padding and hide some content all together.
Make it smaller Mobile devices have smaller screens and therefore you should be coding your email so that the @media query will shrink the width of your email to about 300 pixels eliminating the need to zoom in or pan out.
Turn off font resizing Mobile devices use a browser (Webkit) that will automatically adjust the text size for better viewing on your device. If you make all of the changes above it is a good idea to add some code to turn this feature off. You can do that by applying the following CSS to your body tag: <body style="-webkit-text-size-adjust:none;">
Highlight the important stuff Place all important messages in the upper portion of the email if possible. No one likes to scroll down forever.
Hide low priority content In order to ensure maximum scanability of your email on a mobile device you can hide secondary content by adding the hide class to any image, paragraph or entire table.
Use a single column design A single column makes it easier to quickly browse through an email. If you decide to use more columns for secondary content you can always choose to hide them for mobile.
Be touch friendly Design your buttons a little bigger so they easy to click without having to zoom in.
Test, test and test some more Don’t forget to test your new email design on all platforms. Think about how it will look in a vertical pane as well as horizontal.