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ERROR TYPE Target

Outlook Email Broken Layout Fix: Resolve CSS Flexbox Collapse for Client Rendering Engine Anomalies

Email client rendering variations are caused by differences in parser engines. Legacy Outlook engines ignore modern block models, forcing layouts to stack vertically. Below is the targeted integration guide to fix CSS Flexbox Collapse inside Outlook 2019 templates when using SendGrid.

Technical Breakdown

Outlook 2019 uses the Microsoft Word (MSO) which lacks support for standard rendering rules. This causes CSS Flexbox Collapse elements to break or collapse when rendering templates.

SendGrid Behaviors

SendGrid's template parser automatically injects custom style tags that can override inline styles. Always use inline style definitions and define clear target widths. Test layout code regressions side-by-side using the Campaign Diff Comparator before pushing visual style changes to your production templates.

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 SendGrid 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

Interactive SendGrid Custom Sandbox

Target Environment: Outlook 2019

How to Deploy inside SendGrid

1

Copy the fixed VML or table wrapper code block from the remediation box above.

2

Open SendGrid Design Editor, toggle the view mode to Code Editor, or insert a custom 'Code' module block inside your drag-and-drop layout. Drop the corrected code inside the box.

Targeted Fixes by Use Case & Industry