If you are going to send a CSS-based HTML mail aka Email Templates, chances are you are embedding CSS in <style> tag and end up having a bad experience of not having a properly rendered page.
The issue is that web clients like Gmail etc strip markup tags. Specially <head><script> and <style> for security reasons. The only way is left to make HTML content with inline CSS.
But.. making inline CSS is a pain in the neck and it’s not easy especially when are now used to making external CSS files or style blocks. Thankfully, Mailchimp provides a tool that takes your CSS and HTML and make it online.
Try the CSS Inline tool. It’s quite a neat tool and even takes care of messy CSS
