Outlook Email Broken Layout Fix: Resolve CSS Flexbox Collapse for Deliverability & Spam Audits
Spam filters analyze email HTML code quality alongside body copy. Unclosed tags, excessive styling block nesting, and broken link parameters are flagged as spam risks. Below is the targeted integration guide to fix CSS Flexbox Collapse inside Outlook App (iOS & Android) templates when using Klaviyo.
Technical Breakdown
Outlook App (iOS & Android) uses the WebKit / Blink Wrapper which lacks support for standard rendering rules. This causes CSS Flexbox Collapse elements to break or collapse when rendering templates.
Klaviyo Behaviors
Klaviyo's drag-and-drop template parser automatically wraps all user-defined block sections in proprietary 'kl-part' class selectors. When rendering templates inside Microsoft Word engines (Outlook 2007-2021), Klaviyo's nested flex fallback blocks can cause structural tables to collapse or shift columns. You must use explicit table widths to override Klaviyo's styling wraps. Run your finished layouts through the Spam Word Auditor to catch trigger phrases and verify structural delivery alignments before launching.
Remediation Code Block
To resolve this, modern layouts must be compiled down to Outlook-compliant nested HTML table models. Each flex container becomes a table row, and each flex child becomes a table data cell (td) with explicit pixel or percentage widths. In your Klaviyo campaign manager, make sure you configure your links to run via {% unsubscribe %}.
<table role="presentation" border="0" cellpadding="0" cellspacing="0" width="100%">
<tr>
<td width="50%" valign="top" style="padding: 20px;">Column 1</td>
<td width="50%" valign="top" style="padding: 20px;">Column 2</td>
</tr>
</table>Live Code Sandbox Test
How to Deploy inside Klaviyo
Copy the fixed VML or table wrapper code block from the remediation box above.
Open your Klaviyo template editor. Drag an 'HTML' block directly into your layout timeline (do not use a standard text box). Clear the default skeleton content inside the Klaviyo markup editor and paste the RenderOps corrected inline code.