Emails in Case Feed May Render Differently in Certain Scenarios Compared to the Email Message Detail Page

This article explains why an email may look different when viewed in the Salesforce Case Feed compared to the Email Message detail page, and how to identify and address HTML markup issues in the email body.

Why Emails Render Differently in Case Feed

This behavior is working as designed. When Salesforce processes emails for the Case Feed, it performs dynamic HTML truncation based on content length and markup complexity to ensure optimal page performance. This may cause the email to appear differently in the Case Feed compared to the Email Message detail page, where the original, unmodified HTML is displayed.
Example: If a customer sends an email containing an unclosed <div> tag, Salesforce may truncate the HTML at that point when rendering it in the Case Feed to prevent page rendering issues. The complete, untruncated email is always accessible on the Email Message detail page.

How to Validate Email HTML Markup

One common cause of rendering differences is invalid HTML markup in the email body. Invalid markup includes: invalid comments, unclosed tags, incorrect tag usage, unordered tags, and invalid attributes.
To check whether an email's HTML is valid, use the publicly available https://validator.w3.org/. Paste the HTML source code of the email into the validator to identify and address markup issues. Once the HTML is corrected, future emails from the same sender should render consistently in both the Case Feed and the Email Message detail page.

Accessing the Full Email

Users can always access the complete, untruncated version of an email by navigating to the Email Message detail page for that email record in Salesforce. This page displays the original HTML exactly as received, without any truncation or modification applied by the Case Feed rendering process.