Outlook Email Broken Layout Fix: Resolve Max-Width Constraint Collapsing 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 Max-Width Constraint Collapsing inside Outlook 2021 templates when using Campaign Monitor.
Technical Breakdown
Outlook 2021 uses the Microsoft Word (MSO) which lacks support for standard rendering rules. This causes Max-Width Constraint Collapsing elements to break or collapse when rendering templates.
Campaign Monitor Behaviors
Campaign Monitor wraps custom blocks in dynamic edit tags, which can break the column flow inside Outlook. Ensuring correct class names is essential. 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 secure design widths, always wrap your layout inside a parent table with a static, hardcoded HTML width attribute (e.g. width='600') targeting Microsoft clients using conditional comments. In your Campaign Monitor campaign manager, make sure you configure your links to run via [unsubscribe].
<!--[if mso]>
<table role="presentation" align="center" border="0" cellpadding="0" cellspacing="0" width="600">
<tr>
<td>
<![endif]-->
<div style="max-width: 600px; margin: 0 auto;">
Centered Layout Content
</div>
<!--[if mso]>
</td>
</tr>
</table>
<![endif]-->Live Code Sandbox Test
How to Deploy inside Campaign Monitor
Copy the fixed VML or table wrapper code block from the remediation box above.
In Campaign Monitor, click the 'Source' button on your selected editable text region, or edit the template code files directly. Ensure you append the 'class="cs-editable"' flag if you need inline editing later.