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Email Client Compatibility

Ensure your emails render perfectly across all major email clients. Learn about client differences, common issues, and proven strategies for maximum compatibility.

Market Coverage

95.7%
Market Coverage
15+
Email Clients
3
Device Types
100%
Real-time Analysis

Major Email Clients

Gmail Desktop

Webmail27.8% market shareexcellent

Features Support

CSS Support:Excellent
Responsive:Good
Images:Good

Key Limitations

  • Some CSS3 properties blocked
  • Limited @font-face support

Testing Tips

Use web-safe fonts with fallbacksTest interactive elements thoroughly

Common Compatibility Issues

Flexbox Support

High Impact
CSS Layout

Affected Clients:

Outlook 2007-2019Some older mobile clients

Solution:

Use table-based layouts with CSS fallbacks

Code Example:

<!-- Instead of flexbox -->
<div style="display: flex;">
  <div>Column 1</div>
  <div>Column 2</div>
</div>

<!-- Use tables -->
<table style="width: 100%;">
  <tr>
    <td style="width: 50%;">Column 1</td>
    <td style="width: 50%;">Column 2</td>
  </tr>
</table>

Background Images

Medium Impact
Images

Affected Clients:

Outlook all versionsGmail with images disabled

Solution:

Use solid colors as fallbacks and VML for Outlook

Code Example:

<!-- With VML fallback for Outlook -->
<!--[if mso]>
<v:rect fill="true" stroke="false" style="width:300px;height:200px;">
<v:fill type="tile" src="background.jpg" color="#cccccc" />
<v:textbox>
<![endif]-->
<div style="background: #ccc url('bg.jpg'); width:300px; height:200px;">
  Content here
</div>
<!--[if mso]>
</v:textbox>
</v:rect>
<![endif]-->

Web Fonts

Low Impact
Typography

Affected Clients:

Outlook all versionsSome mobile clients

Solution:

Always provide web-safe font fallbacks

Code Example:

/* Good font stack */
font-family: 'Custom Font', Arial, Helvetica, sans-serif;

/* Better with more fallbacks */
font-family: 'Custom Font', -apple-system, BlinkMacSystemFont, 
             'Segoe UI', Arial, Helvetica, sans-serif;

Testing Strategies

Progressive Enhancement

Start with a solid foundation that works everywhere, then enhance for modern clients.

  1. 1.Create basic layout with tables
  2. 2.Add CSS enhancements for modern clients
  3. 3.Test fallbacks in limited clients
  4. 4.Progressive enhancement with media queries

Device-First Testing

Test on actual devices and email clients, not just preview modes.

  1. 1.Test on real mobile devices
  2. 2.Check desktop email clients
  3. 3.Verify webmail in different browsers
  4. 4.Test with images blocked/enabled

Automated Testing

Use MailLinter's compatibility analysis for consistent testing.

  1. 1.Set up automated email sending
  2. 2.Review compatibility reports
  3. 3.Track improvements over time
  4. 4.Integrate with CI/CD pipeline

Best Practices

Layout

  • Use table-based layouts for maximum compatibility
  • Set explicit widths and heights
  • Use cellpadding and cellspacing for spacing
  • Nest tables for complex layouts

CSS

  • Inline CSS for critical styles
  • Use CSS in <head> for progressive enhancement
  • Avoid float, position, and display properties
  • Test with CSS disabled

Images

  • Always include alt text
  • Use absolute URLs for images
  • Optimize for high DPI displays
  • Provide text fallbacks for blocked images

Content

  • Include both HTML and plain text versions
  • Keep subject lines under 50 characters
  • Use descriptive link text
  • Test with real content, not Lorem Ipsum

What's Next?

Start Testing Now

Ready to test your emails? Get MailLinter running in under 2 minutes.

Advanced Compatibility Tips

Testing Workflow

  • • Test in order: Outlook → Gmail → Apple Mail
  • • Always test with images blocked first
  • • Use MailLinter's preview modes extensively

Code Organization

  • • Keep critical CSS inline
  • • Use progressive enhancement for modern features
  • • Comment your compatibility hacks