How to troubleshoot blank email content issues in Pardot/MCAE?

Key findings

• Inconsistent delivery: Blank email content issues often affect only a subset of recipients within the same domain, suggesting client-specific rendering problems rather than a complete block.
• Subject line present: If the subject line is visible but the body is not, it indicates the email was delivered but could not be rendered, pointing towards HTML/CSS issues.
• Pardot/MCAE opens: A discrepancy in open tracking (some recipients registering opens, others not) for the same email can signal rendering failures preventing tracking pixels from loading.
• Template cloning: Cloning older email templates can inadvertently carry over outdated or problematic HTML/CSS that may not be compatible with newer email clients or strict rendering engines.
• Conditional comments: Nested MSO (Microsoft Office) conditional comments are a frequent source of rendering errors in older Outlook versions and Office 365, leading to blank content.

Key considerations

• Raw message analysis: Obtaining the full, raw email message (as an .eml file) from an affected recipient is crucial for diagnosing issues. This allows for inspection of the exact content received, including HTML that might be base64 encoded.
• Decoding content: HTML and plain text parts within an email can be base64 encoded. Tools that decode base64 strings are essential for reviewing the actual content. A useful resource for this is the encoding tool from Word to the Wise.
• Testing email rendering: Utilize email rendering testing platforms (like Litmus) to preview how your emails appear across various email clients and devices. This proactive step can identify rendering issues before sending. Learn more about diagnosing email rendering variances.
• Review HTML/CSS: Pay close attention to conditional CSS and HTML structures, especially those targeting specific email clients like Outlook. Salesforce's Trailhead community has discussions on HTML email issues. Nested or malformed tags can lead to content stripping.
• Rule out security filters: While security filters can strip content, they often leave indicators or quarantine the email entirely. If the email arrives with only a subject line, a rendering problem is more likely. If you're seeing blank emails for some, consider other reasons why emails might be blank.

Key opinions

• Outlook's historical issues: Many marketers are accustomed to Outlook being a primary source of email rendering headaches, particularly with its proprietary MSO conditional comments.
• Importance of testing platforms: Using tools like Litmus is a common and highly recommended practice to proactively catch rendering issues across diverse email clients before deployment.
• HTML validation is key: Marketers emphasize the need to scrutinize email HTML for errors, especially nested tags or incorrect syntax, which can lead to content disappearing.
• Cloning pitfalls: While convenient, cloning old email templates can perpetuate existing HTML or CSS problems that might only surface with specific client versions.
• Distinguishing from spam filters: Marketers often distinguish rendering issues from spam filtering. If a subject line is present but the content is blank, it's more likely a rendering glitch than a blacklist or blocklist issue.

Key considerations

• Recipient environment variations: Consider that different recipients at the same domain might use different email client versions or have unique security settings, leading to varied rendering.
• Impact on engagement: Blank emails prevent opens and clicks from being tracked, directly impacting campaign performance metrics and potentially leading to low email engagement.
• Pardot/MCAE specifics: Be aware of how Pardot/MCAE handles email templates, including any platform-specific HTML wrappers or validation rules that might interact with custom code. For more on platform-specific issues, see Knak's guide to troubleshooting Pardot emails.
• Template updates: If a template was recently changed, even slightly, it could introduce new rendering issues. This is similar to troubleshooting Microsoft emails after a template change.

Key opinions

• Raw message is king: Experts consistently stress that only the complete, raw email message (often in .eml format) provides sufficient data to troubleshoot rendering problems accurately.
• Filter defanging less likely: A security filter 'defanging' or stripping content usually leaves some trace or quarantines the email, making it a less probable cause for entirely blank emails with only a subject line.
• Rendering corruption: Often, blank content is a sign of 'weird message corruption' or a 'rendering issue' resulting from the interaction between email structure and client software, sometimes even without a spam filter involved.
• Base64 encoding common: It's normal for email content (both plain text and HTML) to be base64 encoded, and decoding this is a standard step in forensic email analysis.
• Forwarded emails are limited: While a forwarded email can provide some insight, it's not ideal for full diagnostics as crucial headers or multipart boundaries might be altered or missing.

Key considerations

• Technical expertise: Troubleshooting blank content requires a technical understanding of email message structure, including MIME types, multipart boundaries, and encoding methods like base64. This is part of how email experts troubleshoot customer issues.
• Verification of content integrity: After decoding, verify that the HTML or plain text content is exactly what was expected. Any discrepancies indicate a modification in transit or a source issue.
• Client-specific HTML: Issues often stem from email code that performs well in most clients but fails in specific, often older, versions of Outlook due to its non-standard rendering engine. This is particularly relevant when considering why email templates might not show up.
• Authentication checks: While less direct to blank content, ensuring proper authentication (like SPF and DKIM) helps guarantee the email itself isn't being flagged before rendering issues even arise. See our guide on troubleshooting SPF validation errors in Pardot.

Key findings

• Outlook's rendering engine: Documentation confirms that Outlook uses Microsoft Word's rendering engine, which has unique quirks and often requires specific MSO conditional comments to display HTML emails correctly.
• Conditional comment structure: Incorrect nesting or syntax within MSO conditional comments can lead to unexpected rendering behavior, including the complete omission of content sections.
• HTML standard deviations: Many email clients, including various versions of Outlook, do not fully support modern HTML and CSS standards, necessitating a more conservative coding approach for broader compatibility.
• Multipart/alternative messages: Emails typically contain both HTML and plain text parts. If the HTML part fails to render, some clients may fall back to the plain text, but if both are malformed or missing, the email appears blank.
• Email pre-processors: Platforms like Pardot/MCAE might apply their own processing to email HTML, which can sometimes interfere with complex custom code if not handled carefully.

Key considerations

• Robust testing matrix: Documentation for email development tools emphasizes the critical need to test emails across a wide array of clients, including different versions of Outlook, to catch rendering inconsistencies.
• Valid HTML/CSS for email: Adhering to widely accepted email HTML/CSS best practices, often simpler than web development, can prevent unexpected rendering failures. Even for Salesforce Marketing Cloud troubleshooting, HTML structure is vital.
• Pardot/MCAE email best practices: Consult Salesforce's own documentation for specific guidelines on building emails in Pardot/MCAE, particularly concerning custom HTML and dynamic content, as platform-specific nuances can affect rendering.
• Firewall/security impact: While less likely for blank content, enterprise security systems can sometimes strip specific elements. Mithi's help center discusses blank emails on Salesforce addresses in relation to Salesforce. This is relevant to troubleshooting deliverability to specific business domains.