Though you can definitely use CSS (Cascading Style Sheets) for HTML email styling, there are a few restriction that an e-mail template developer should be aware of. The short version is: use CSS preferably inline and mainly for simple elements like color and fonts.
Some rules of thumb:
- Don’t use CSS for positioning.
- Yse CSS for fonts and colors.
- Be aware that WYSIWYG editors might add not supported styling elements.
- Use CSS preferably inline only, though support for embedded styles in the email <head> is growing.
- Always test your layout and styling using the available tools.
The CSS attributes below are supported by most popular e-mail clients: