Fixing Layout and Rendering Issues in Email Templates for Older Outlook Versions

Overview

Emails designed in Unlayer (or similar builders) may experience layout and rendering issues in older versions of Microsoft Outlook due to its reliance on the Microsoft Word rendering engine. This results in inconsistent support for HTML and CSS standards compared to more modern email clients like Gmail or Yahoo Mail. Frequent challenges include stripped-out HTML elements, misaligned tables, spacing issues, and broken CSS properties. To address these issues, below we outline the main causes and provide best practices for creating emails that render correctly in older Outlook versions.

Causes of Layout Issues in Older Outlook Versions

HTML Stripping: Certain HTML elements exported from the builder may be removed or altered when emails are sent independently, leading to broken layouts. It is crucial to compare the original HTML code with the sent email’s HTML to pinpoint discrepancies.
Microsoft Word Rendering Engine: Outlook uses the Word engine to render emails, which supports limited HTML/CSS features. For example: - Complex CSS properties like floats, positioning, or advanced animations may not work as expected. - Outlook often rebuilds HTML structures (especially in forwarded or replied emails), creating alignment or formatting issues.

Best Practices for Improved Compatibility

To make email templates more compatible with Outlook:

Use Table-Based Layouts: Structure emails using nested tables instead of modern div-based layouts. This ensures better rendering consistency.
Avoid Complex CSS: - Avoid CSS properties like floats, position, or video embedding. - Stick to simple, robust inline CSS for styling. Ensure all styles are hardcoded into individual elements. - For background images, use VML (Vector Markup Language) for compatibility and provide solid color fallbacks.
Define Dimensions Explicitly: - Set fixed widths and heights for images, tables, and other elements to avoid resizing issues. - Use explicit cell padding and margins via table attributes rather than relying on CSS alone.
Minimize Conditional Styles for Outlook: - Use Microsoft-specific "MSO" conditionals sparingly to target Outlook-specific fixes. - Avoid designs dependent on precise pixel spacing across clients.
Test Across Outlook Versions: - Always test your email templates in different versions of Outlook, focusing on alignment and spacing. - Use email testing tools to preview your design in Outlook before deployment.

Troubleshooting and Tools for Addressing Issues

Compare HTML Code: When problems appear, compare the original HTML exported from Unlayer with the sent email HTML to identify what might have been stripped out.
Use Email Testing Tools: Platforms like Litmus or Email on Acid can provide previews of how your email will render in Outlook and other email clients.
Simplify Complex Designs: If issues persist, consider simplifying your layout and avoiding elements that heavily rely on modern CSS techniques.

Conclusion

Rendering and layout issues in older versions of Outlook stem primarily from limitations in its rendering engine and how HTML/CSS is processed. By adopting table-based layouts, inline styles, and rigorous testing, you can significantly improve compatibility and ensure your email templates display consistently across all email clients. Use the practices and troubleshooting tips shared above to craft templates that function well even in restrictive environments like Outlook.

How can I fix layout and rendering issues in email templates for older versions of Outlook?