Why do some email clients show my email differently than others?
There are a lot of reasons that email clients display the same code different. Most clients use some kind of preprocessor that will modify your code. In the case of Gmail, this means stripping out IDs and classes, as well as certain CSS rules such as “float.” Outlook 07, 10 and 13 will convert your email to a Word document before displaying it, which can wreak havoc on even the most carefully coded email.
Beyond these differences, your email may look different in browsers set to different widths, or on different devices. For these reasons, we recommend that you thoroughly test your email before sending!