Fix Gmail 102KB Layout Clipping in Apple Mail (Desktop) — Campaign Monitor Guide for WCAG Accessibility Violations
Accessibility failures prevent screen readers from navigating templates, isolating disabled subscribers and increasing unsubscribe rates. Below is the targeted integration guide to fix Gmail 102KB Layout Clipping inside Apple Mail (Desktop) templates when using Campaign Monitor.
Technical Breakdown
Apple Mail (Desktop) uses the WebKit which lacks support for standard rendering rules. This causes Gmail 102KB Layout Clipping 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. Inject correct table roles (role='presentation') and keep color pairings above the WCAG AA contrast threshold of 4.5:1.
Remediation Code Block
To resolve this, you must run your layouts through a specialized tree-shaking parser. Unused CSS selectors must be shaken off, styling rules inlined, comments removed, classes shortened, and layouts compressed to fit well under 100KB. In your Campaign Monitor campaign manager, make sure you configure your links to run via [unsubscribe].
<!-- Minified, compiled, and tree-shaken HTML email markup (under 80KB) -->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.