Drag-and-drop responsive emails that render correctly in Gmail, Outlook, Apple Mail and Yahoo. Let AI draft and refine them, preview how each client renders, then export clean HTML you can send from anywhere.
No account to build · Templates stay in your browser · Export to any ESP
Outlook renders email with Microsoft Word.
No max-width, no border-radius, no flexbox, no background images on divs. A layout that looks perfect in your browser collapses into a mess.
Gmail clips large messages.
Anything over 102KB gets truncated behind a “View entire message” link — often hiding your unsubscribe link, which hurts deliverability.
Every client is different.
What works in Apple Mail fails in Outlook; what works in Outlook looks dated in Gmail. Writing email HTML by hand means maintaining twenty years of hacks.
Kettlemail solves this by never letting you write fragile HTML in the first place: your design compiles through MJML, the industry-standard email framework, producing table-based markup with every client-specific fallback already in place.
Building, the AI studio, attention prediction, per-client previews, code access and export are all free and open source — no account, no watermark, no locked features.
Sections, columns, text, buttons, images, dividers, social, tables and more — drop them where you want. Undo/redo, autosave and inline text editing included.
Your design compiles through MJML to bulletproof table-based HTML — Outlook ghost tables, VML buttons and mobile media queries generated automatically.
Rewrite your whole email in plain language, fix any single block, or generate five subject-line + preview-text options. The AI edits real MJML, so nothing ever breaks.
See what a reader notices in the first 3-second glance — a predicted heatmap, scan path and plain-language verdicts like “your CTA misses the first glance.”
Watch your email degrade the way each client actually renders it — side by side — plus a compatibility linter and a live Gmail 102KB size meter.
A real code editor with round-trip MJML sync: tweak the markup or drop in raw HTML for merge tags, and keep using the visual builder side by side.
Three AI surfaces work on the same MJML the editor uses — so the assistant can never produce an email that breaks. Every change is one undo away.
“Make this a dark-mode product launch and fix the issues” — full-document edits that read your real linter, size and attention findings.
Select any block and refine just that block: stronger call-to-action, fix grammar, split into two paragraphs — cheap, fast, scoped.
Generate five subject-line + preview-text pairs across distinct angles, shown as simulated inbox rows. Apply one in a click.
A predicted attention heatmap, numbered scan path and fold line show what a reader sees in the first glance — with verdicts you can act on. An honest heuristic, not eye-tracking.
Preview each client’s real degradation side by side — Outlook’s Word engine, Gmail clipping, forced dark-mode inversion — with a note for every change the client makes.
Send a genuine test email to your own inbox for ground truth — plus a compatibility linter and Gmail size meter that flag problems while you build.
Download one self-contained .html file with all CSS inlined — or grab the .mjml and re-importable .json. It drops straight into every major email platform and sender.
Paste into the custom-HTML / code editor of any campaign tool.
Drop the HTML into your transactional templates or send it directly.
If your platform accepts custom HTML — and they all do — your Kettlemail export works there.
Drag sections and blocks onto the canvas, or ask the AI to draft it. Style everything in the settings panel — colors, fonts, spacing, links.
See the real compiled email at desktop and mobile widths, run Client Lens per client, check the linter and the Gmail size meter.
Send a real test email to your own inbox to confirm it renders before you ship — no guesswork.
Download one clean HTML file and paste it into any email platform or sender. Done.
Yes — it's free and open source. The builder, preview, code editor, AI features and HTML export are all free, with no account required. Your templates are stored in your own browser, so we never see them.
Outlook for Windows renders email with Microsoft Word's engine, which ignores modern CSS like max-width, border-radius and flexbox. Kettlemail compiles your design to table-based HTML with Outlook-specific fallbacks (ghost tables, VML buttons) generated automatically, so it renders correctly without you writing a single hack.
Exported templates use the battle-tested MJML engine and render correctly in Gmail (web, iOS, Android), Outlook (Windows desktop, Mac and web), Apple Mail, iOS Mail, Yahoo Mail and Samsung Mail.
Yes. The Code tab shows your template as editable MJML markup that stays in sync with the visual editor, and you can add raw HTML blocks for things like merge tags. The compiled HTML output is also viewable and copyable at any time.
Yes. The export is a single self-contained HTML file with all CSS inlined. Paste it into the custom-HTML option of any email platform — Mailchimp, Brevo, SendGrid, Klaviyo, HubSpot, Constant Contact — or send it via any API or SMTP service like Resend, Amazon SES, Mailgun or Postmark.
Describe changes in plain language and the AI rewrites your template — safely, because it edits the same MJML the visual editor uses. It can restyle whole emails, fix a single block (Magic Edit), or generate five subject-line and preview-text options (Inbox Studio). Every AI change is a single undo away. When self-hosting, add your own AI provider key to enable these features.
Gmail clips messages larger than 102KB, hiding the rest behind a 'View entire message' link. Kettlemail shows a live size meter while you build and warns you before you export anything Gmail would clip.
Free, AI-assisted, and it works in every major email client and ESP.
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