Outlook Email Broken Layout Fix: Resolve Max-Width Constraint Collapsing 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 Max-Width Constraint Collapsing inside Outlook 2019 templates when using Campaign Monitor.
Technical Breakdown
Outlook 2019 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. Run your finished layouts through the Spam Word Auditor to catch trigger phrases and verify structural delivery alignments before launching.
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.