Fix Padding & Margin Collapsing in iOS Mail (Apple) — Campaign Monitor Guide 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 Padding & Margin Collapsing inside iOS Mail (Apple) templates when using Campaign Monitor.
Technical Breakdown
iOS Mail (Apple) uses the WebKit Mobile which lacks support for standard rendering rules. This causes Padding & Margin 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. 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 ensure spacing works reliably, apply all structural paddings directly to HTML td elements inside tables. Do not apply paddings or margins to raw divs, as Outlook will strip them. For vertical spacing, use explicit spacer tables or empty rows. 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 height="20" style="font-size: 1px; line-height: 1px;"> </td>
</tr>
<tr>
<td style="padding: 15px; background-color: #f1f1f1;">
Content with padding and margin
</td>
</tr>
<tr>
<td height="20" style="font-size: 1px; line-height: 1px;"> </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.