HTML Email Rendering Broken Across Email Clients
HTML emails generated by your Cursor-built application look great in the preview or in one email client, but are completely broken in others. Layouts collapse in Gmail, images don't load in Outlook, fonts revert to defaults in Yahoo Mail, and dark mode inverts your carefully chosen colors.
HTML email rendering is stuck in 1999 — email clients use wildly different HTML/CSS engines. Outlook uses Microsoft Word's HTML renderer, Gmail strips most CSS, and Apple Mail has its own quirks. Cursor generates modern HTML/CSS that works perfectly in browsers but violates almost every constraint of email client rendering.
The issue affects your brand perception and functionality. Broken emails look unprofessional, can obscure important content like verification links, and may even trigger spam filters that look for malformed HTML.
Error Messages You Might See
Common Causes
- External CSS stylesheets — Cursor linked to an external CSS file or used
<style>blocks in the head, which Gmail and many clients completely strip - Modern CSS properties — Flexbox, Grid, CSS variables, and media queries are unsupported in most email clients, especially Outlook
- Div-based layout — Cursor generated div-based layouts instead of table-based layouts, which are the only reliable layout method for email
- Images without alt text or dimensions — Images block loading by default in many clients. Without explicit width/height attributes, layouts break when images are hidden
- Web fonts and custom fonts — Custom font imports are ignored by most email clients, causing text to render in fallback system fonts with different sizing
- Dark mode not handled — Email clients' dark mode inverts colors unpredictably, making light text on light backgrounds or dark text on dark backgrounds
How to Fix It
- Use inline CSS only — Move all styles to inline style attributes on each HTML element. Use a CSS inliner tool like juice or Premailer to automate this conversion
- Use table-based layouts — Replace all div layouts with nested
<table>elements. Userole="presentation"for accessibility. This is the only reliable cross-client layout method - Use a tested email framework — Replace Cursor's custom HTML with a battle-tested email framework like MJML, React Email, or Maizzle that compiles to compatible HTML
- Add explicit image dimensions — Always include width and height attributes on img tags, and add alt text so content makes sense when images are blocked
- Test across email clients — Use Litmus or Email on Acid to preview your emails in 90+ email clients before sending
- Handle dark mode explicitly — Add
@media (prefers-color-scheme: dark)styles and use thecolor-schememeta tag. Provide both light and dark versions of logos
Real developers can help you.
Jen Jacobsen
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hanson1014
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Basel Issmail
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Get HelpFrequently Asked Questions
Why can't I use modern CSS in emails?
Email clients use different rendering engines than browsers. Outlook uses Microsoft Word's HTML renderer (which barely supports CSS2), Gmail strips all CSS from the head and only keeps inline styles, and each client has its own quirks. Stick to inline CSS, table layouts, and basic CSS properties.
What is the best way to create HTML emails?
Use a purpose-built email framework: MJML (markup language that compiles to compatible HTML), React Email (for React developers), or Maizzle (Tailwind CSS for emails). These frameworks handle cross-client compatibility so you don't have to.