Media queries are essential for creating responsive emails. They allow the email layout to adapt to different screen sizes. Here's an example of how to use media queries: @media only screen and (max-width: 600px) { .container { width: 100% !important; } .content { font-size: 16px !important; } } In this example, the container width and font size will adjust when the screen width is 600px or smaller, ensuring the email looks good on mobile devices.