What is responsive HTML email template?
Responsive emails are characterized by elements appearing below one another, rather than next to each other, when displayed on a smaller screen. In order to achieve this, it is necessary that you create separate elements. Say, you want to create two columns of content.
Can you put CSS in emails?
CSS will work in HTML email but it has limitations. In general, very simple CSS is always best when you code for email. These are our recommendations for how to use CSS in HTML email and some information to help you troubleshoot CSS-related issues.
Can I email CSS?
There is nothing stopping you from creating an email that is completely laid out with CSS grid. Some email clients will support it, and some won't. When it is supported, a fancy layout happens.
Responsive email design best practices
Stick to a single column layout. Less shifting and moving makes it easier for your audience to read your content. At minimum, use 13- or 14-pt font for the body text and no smaller than 20-pt for the titles. This will make your email much more readable on a small screen.