You spent hours designing a beautiful email. It looks flawless in Gmail and Apple Mail. But when you test it in Outlook, the layout is shattered, the padding is gone, images are missing, and your buttons look like plain text links.

This is the most common frustration in email marketing. The problem isn't your design — it's the underlying infrastructure of how Outlook renders HTML. Here is the technical explanation and the exact fixes you need.


The Real Reason Outlook Breaks Emails

Since Outlook 2007, Microsoft made a controversial decision: instead of using Internet Explorer or Edge to render HTML emails, it uses Microsoft Word. Word is a word processor, not a web browser. It has zero support for modern CSS. If your email builder uses div tags, floats, or CSS padding on containers, Word simply ignores them.

How to Fix Common Outlook Rendering Issues

1. Use Table-Based Layouts (Not Divs)

While web design moved away from tables in the 2000s, email design still relies on them for Outlook compatibility. Instead of using div elements for columns, use

, , and
. Apply padding directly to the cell.

2. Bulletproof Buttons

CSS background colors and padding on a tags do not work in Outlook. Your button will lose its background and shrink. Use VML (Vector Markup Language) wrapped in MSO conditional comments to force Outlook to render a clickable rectangle with background color.

3. Fixing Background Images

The standard CSS background-image property is ignored by Outlook. Use VML v:rect and v:fill tags inside an MSO conditional comment to embed the image natively.

4. Image-to-Text Ratio & Alt Text

Outlook blocks images by default. If your email is one giant image, the recipient sees a blank screen. Include descriptive alt text for every image and maintain a 60/40 text-to-image ratio.

About the Author

Syed Raiyan is an email deliverability expert and Mailchimp Pro Partner with 18+ years of experience. He hand-codes bulletproof HTML email templates that render pixel-perfectly across 90+ email clients, including Outlook.

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I hand-code bulletproof HTML email templates using table-based architecture and VML. They render pixel-perfectly across 90+ email clients, including the dreaded Outlook desktop app.

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