Email Client Compatibility

Navigate the complex world of email client support. See which HTML and CSS features work across Gmail, Outlook, Apple Mail, and 40+ other email clients.

Test CompatibilityBest Practices

Major Email Clients

Market share and overall HTML/CSS support levels

📧

Gmail

Market Share: 28%
Excellent Support
📮

Outlook

Market Share: 19%
Limited Support
📬

Apple Mail

Market Share: 15%
Excellent Support
📭

Yahoo Mail

Market Share: 8%
Good Support
🦅

Thunderbird

Market Share: 3%
Good Support
📱

Samsung Email

Market Share: 4%
Good Support

Feature Support Matrix

FeatureGmailOutlookApple MailYahooNotes
CSS Grid
Use table layouts instead
Flexbox
Limited support, avoid for layout
CSS Animations
Apple Mail only
Web Fonts
Always include fallbacks
Background Images
Outlook has VML workarounds
Media Queries
Desktop Outlook lacks support
Supported
Partial Support
Not Supported

Testing Recommendations

Priority Clients

Focus your testing efforts on these high-impact email clients:

  • Gmail (Web & Mobile) - 28% market share
  • Outlook 2016/2019/365 - 19% market share
  • Apple Mail (iOS & macOS) - 15% market share
  • Yahoo Mail - 8% market share

Testing Strategy

Follow this approach for comprehensive email testing:

  • Test desktop and mobile versions
  • Check both light and dark modes
  • Verify with images blocked
  • Test across different screen sizes

Test Your Email Across All Clients

Use our comprehensive testing tool to check compatibility across 40+ email clients.

Start Compatibility Testing