# Email HTML Linter Check email HTML templates for cross-client compatibility: unsupported CSS, non-inline styles, Outlook traps, table layout issues, and accessibility gaps. > Canonical page: https://elysiatools.com/en/tools/email-html-linter - **Category:** Development - **Keywords:** email html, html email, email linter, outlook compatible, gmail render, inline css, vml, table layout, newsletter, email template ## Overview Catch the HTML-email bugs that only show up in Outlook, Gmail, and Apple Mail — before you send. \*\*Why email HTML is different.\*\* Email is still largely 1990s HTML rendered by inconsistent engines: Outlook desktop uses \*\*Microsoft Word\*\* to render HTML (yes, really), Gmail strips most \`\` blocks, Apple Mail is the most forgiving but still quirky. Flexbox, grid, and \`position: fixed\` break in most clients. Tables-based layout is not retro — it is the reliable default. \*\*What this linter checks.\*\* - \*\*Unsupported CSS\*\* — \`display: flex/grid\`, \`position: fixed/absolute\`, \`