Feature Deep Dive
A visual builder is table stakes. What makes ours different is the "Check Compatibility" button. One click runs your email through rendering checks across Outlook, Gmail, Apple Mail, Yahoo, and mobile clients, gives you a score, flags what is likely to break, and lets AI rewrite the email code for compatibility — without changing the message you wrote.
Overview
Design in a visual builder, validate rendering across major inboxes, and fix structural issues in one click — without leaving your marketing platform.
Every marketer knows the pain. You spend an hour designing a beautiful email. It looks perfect in the builder. You send it. Then someone opens it in Outlook Desktop and the background image is gone, spacing is broken, or the layout behaves differently on mobile. Compatibility issues are one of the most frustrating parts of email marketing — and most builders either ignore the problem or expect you to debug it yourself. MartechAI's Email Builder adds a compatibility layer that checks how your email is likely to render across major email clients and can automatically fix the HTML and structure while preserving your actual content.
Click the 'Check Compatibility' button and the AI analyzes your email's HTML against the rendering engines of every major email client: Outlook Desktop (notorious for blocking background colors and CSS), Gmail (strips certain CSS properties), Apple Mail, Outlook.com, Yahoo Mail, and mobile clients. It returns an overall compatibility score (1-10), a list of specific issues per client, and recommendations for fixes.
Click 'Fix' and the AI rewrites your email's code to be compatible across all clients. It converts risky CSS to inline styles, replaces unsupported properties with safe alternatives, restructures layouts to be table-friendly where needed, and handles mobile responsiveness — all while preserving your content, images, links, and copy exactly as you wrote them. What used to take hours of manual CSS debugging now takes one click.
The builder itself is a responsive drag-and-drop editor. Build sections, add images, text blocks, buttons, dividers. Save reusable templates. A/B test subject lines, content, and send times. And the AI that generates your email content knows your brand voice, your GA4 data, your GSC keywords, and what subject lines worked in your last three campaigns — so the copy it writes is actually relevant to your audience.
How It Compares
See how MartechAI's compatibility layer compares to the email builders you may already be using.
Most builders stop at design. Ours checks whether the email will actually hold up. Mailchimp has a polished builder but no AI compatibility checking. Constant Contact has decent deliverability, but no compatibility scoring. Brevo's builder is solid, yet it does not focus on cross-client compatibility fixes. HubSpot's email builder is usable, but it does not give you an AI-powered compatibility audit and one-click rewrite layer. Nobody in this category offers AI-powered email compatibility checking and automatic fixes in the same way.
At a Glance
Six capabilities that separate a design tool from an email workflow your team can trust before send.
AI compatibility check with score (1–10) and per-client issue list.
AI auto-fix rewrites code for Outlook, Gmail, Apple Mail, Yahoo, and mobile.
Preserves content — only adjusts structure, HTML, and styles where needed.
Visual drag-and-drop builder with responsive templates and reusable blocks.
AI content generation from brand voice, GA4 data, campaign history, and keyword context.
A/B testing support for subject lines, content direction, and send timing.
Ready to fix email rendering headaches?
14-day free trial. Email builder, CRM, campaigns, analytics, SEO, and AI — one connected platform, starting at $49/month.