Fix CSS Grid Broken Columns in Mozilla Thunderbird — Campaign Monitor Guide for Transactional & System Notifications
Transactional emails (receipts, password resets, shipping alerts) carry critical operational data. Spacing collapses or broken buttons can block users from completing essential user journeys. Below is the targeted integration guide to fix CSS Grid Broken Columns inside Mozilla Thunderbird templates when using Campaign Monitor.
Technical Breakdown
Mozilla Thunderbird uses the Gecko which lacks support for standard rendering rules. This causes CSS Grid Broken Columns 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. Because system notifications are triggered frequently, ensure your CSS rules are completely inlined to guarantee readability in high-volume, automated delivery queues.
Remediation Code Block
Always compile grid layouts using standard percentage-width or pixel-width nested tables aligned with the align='left' attribute. This acts as a responsive grid block that floats and adapts naturally to any viewport size. In your Campaign Monitor 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="48%" align="left" valign="top" style="padding-bottom:10px;">Col 1</td>
<td width="4%"></td>
<td width="48%" align="left" valign="top" style="padding-bottom:10px;">Col 2</td>
</tr>
</table>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.