Engagement - Marketing Cloud Engagement Email Does Not Display Correctly on a Mobile Device

Mobile email clients vary widely in how they render HTML and CSS — some clients strip `<style>` blocks, block external images by default, or fall back to plain-text rendering when HTML validation fails. This can result in Marketing Cloud emails that display incorrectly on mobile devices, with common symptoms including:

• Images not displaying or showing as broken image placeholders
• Email rendering as plain text with no formatting or images
• Layout appearing broken, misaligned, or overflowing the screen width
• Email rendering differently across mobile clients (Gmail, Apple Mail, Outlook Mobile, Samsung Email)

Use this article to diagnose your specific rendering issue and apply the appropriate fix — from using Mobile Optimized Templates in Content Builder to troubleshooting image hosting and CSS compatibility.