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USE CASE Target

Fix Outlook Background Image Collapse in Mozilla Thunderbird — MJML Framework Guide for eCommerce Campaigns

In eCommerce email marketing, rendering issues directly tank conversion rates and cart recoveries. Product grids, checkout CTAs, and discount banners must display flawlessly to prevent purchase drop-offs. Below is the targeted integration guide to fix Outlook Background Image Collapse inside Mozilla Thunderbird templates when using MJML Framework.

Technical Breakdown

Mozilla Thunderbird uses the Gecko which lacks support for standard rendering rules. This causes Outlook Background Image Collapse elements to break or collapse when rendering templates.

MJML Framework Behaviors

The MJML transpilation compiler parses dynamic columns and wraps them in custom HTML conditional tags. If you paste direct tables or VML code blocks inside an MJML layout without proper escaping, the MJML compiler will try to clean the code, resulting in stripped Outlook namespaces and broken layouts. Double-check your dynamic product feed blocks. When injecting product loops from your catalog, ensure width sizes are explicitly handled to keep columns from overlapping.

Remediation Code Block

To resolve this in Outlook desktop, you must wrap your element or cell inside a Microsoft VML (Vector Markup Language) shapes structure that declares the background image explicitly using the 'v:background' or 'v:fill' vector properties. In your MJML Framework campaign manager, make sure you configure your links to run via {{unsubscribe_link}}.

<td background="https://example.com/bg.jpg" bgcolor="#222222" valign="top" style="background-image: url('https://example.com/bg.jpg'); background-repeat: no-repeat; background-size: cover;">
  <!--[if mso]>
  <v:rect xmlns:v="urn:schemas-microsoft-com:vml" fill="true" stroke="false" style="width:600px;height:300px;">
    <v:fill type="tile" src="https://example.com/bg.jpg" color="#222222" />
    <v:textbox inset="0,0,0,0">
  <![endif]-->
  <div>Overlay Content</div>
  <!--[if mso]>
    </v:textbox>
  </v:rect>
  <![endif]-->
</td>

Live Code Sandbox Test

Interactive MJML Framework Custom Sandbox

Target Environment: Mozilla Thunderbird

How to Deploy inside MJML Framework

1

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

2

Wrap the entire RenderOps corrected table block inside an '<mj-raw>' tag block. This tells the MJML compiler to bypass parsing on this segment, exporting the exact conditional statements into the final HTML output.

Targeted Fixes by Use Case & Industry