Email template optimization tools
Here is the list of email templates optimization tools. Remember to exclude media query if you have for responsive design. They will not work properly if inline. Some time might face a problem that your responsive design is not working on some of the email clients. The reason might be of character limit. The stylesheet is then checked against a 8,192 character limit. If your stylesheet, after processing, exceeds the limit, the whole stylesheet gets removed from your email.