Fix Default Image Blocking Layouts in iOS Mail (Apple) — SendGrid 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 Default Image Blocking Layouts inside iOS Mail (Apple) templates when using SendGrid.
Technical Breakdown
iOS Mail (Apple) uses the WebKit Mobile which lacks support for standard rendering rules. This causes Default Image Blocking Layouts elements to break or collapse when rendering templates.
SendGrid Behaviors
SendGrid's template parser automatically injects custom style tags that can override inline styles. Always use inline style definitions and define clear target widths. 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, always define explicit width and height attributes on your images to preserve their layout boxes when blocked. Add robust alternative (ALT) text styled with CSS font-sizes and colors, and encode vital brand logos directly as Base64 data URIs. In your SendGrid campaign manager, make sure you configure your links to run via {{{unsubscribe}}}.
<img src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAADIA..." width="150" height="40" alt="Company Logo" style="display: block; font-family: sans-serif; font-size: 14px; color: #111111; font-weight: bold; border: 0;">Live Code Sandbox Test
How to Deploy inside SendGrid
Copy the fixed VML or table wrapper code block from the remediation box above.
Open SendGrid Design Editor, toggle the view mode to Code Editor, or insert a custom 'Code' module block inside your drag-and-drop layout. Drop the corrected code inside the box.