Code validators scan the HTML and CSS code to identify issues based on predefined rules and standards. These tools check for:
Syntax Errors: Incorrect tags, missing attributes, or misplaced elements. Compatibility Issues: Elements or styles that may not be supported by certain email clients. Accessibility Concerns: Missing alt text for images, insufficient contrast, or lack of ARIA roles. Best Practices: Ensuring proper use of tables for layout, inline CSS for styling, and avoiding unsupported JavaScript.