HTML Email Templates: Why They Break and How to Build Ones That Don’t

Building an HTML email template feels like time travel. Email clients — especially Outlook — render with ancient engines, so the modern CSS you use on the web simply does not apply.

Why email HTML breaks

There is no shared standard. Gmail strips <style> in some contexts, Outlook uses Word's rendering engine, and dark mode rewrites your colors. What looks perfect in one client collapses in another.

Rules that survive everywhere

• Use tables for layout, not flexbox or grid.
• Use inline styles, not external or embedded CSS.
• Keep width around 600px and design mobile-first.
• Always ship a plain-text version alongside the HTML.

Test before you trust

Send to real Gmail, Outlook, Apple Mail and Yandex inboxes before any campaign. A template that passes your eye in the browser can still shatter in a client.

Or skip the hand-coding

Sendersy's visual editor outputs table-based, inline-styled HTML that renders consistently, plus a text fallback automatically. Start free and build a bulletproof template without touching markup.