Why are some email subscribers receiving blank emails and how can I fix it?
Matthew Whittaker
Co-founder & CTO, Suped
Published 14 May 2025
Updated 17 Aug 2025
8 min read
Dealing with email subscribers who report receiving blank emails can be incredibly frustrating. It's an issue that impacts user experience and can severely hinder your communication efforts. When emails arrive without a subject, header, footer, or body content, it signals a deeper problem than just a message going to the spam folder. This scenario suggests that the email content itself is being stripped or is failing to render correctly at some point in the delivery or display process.
The challenge is that the root cause isn't always obvious. It could be due to issues on the sender's side, problems with the recipient's email provider, or even how the email client interprets the message. I've encountered instances where specific internet service providers (ISPs), like Shaw.ca, appear to be filtering or blocking content, making direct diagnosis difficult without their cooperation. Understanding where the breakdown occurs is the first step toward a solution.
Pinpointing the root cause
When a subscriber reports a blank email, the immediate reaction might be to ask them to forward the message. However, this is rarely an effective diagnostic step. When an email is forwarded, the recipient's email client often creates a *new* email and inserts what it *thinks* is the original content. If the original content was already stripped or failed to render, the forwarded version will likely reflect that, showing a blank or nearly empty message, even if the original raw source contained content.
A more reliable method is to ask the subscriber to forward the email as an attachment, or if possible, to retrieve the raw email source. The raw source, often accessible through a view source option in their email client, provides the complete, unaltered message including headers and HTML/plain text body parts, giving you a true picture of what was received at their mail server before rendering.
Another crucial step is to determine the specific email client or webmail interface the subscriber is using. An email appearing blank in Outlook might display perfectly fine in Gmail's web interface. This distinction helps narrow down whether the issue is with the email content itself or with how a particular client renders it. Some clients have stricter rendering engines or security settings that might block or strip certain content.
To proactively diagnose, running an inbox placement test is invaluable. These tests send your email to a network of seed addresses across various ISPs and email clients, allowing you to see exactly how your email is delivered and rendered. If a specific ISP or client consistently shows blank emails, it points towards a systematic issue needing further investigation with that provider.
Common technical culprits
Several technical issues can lead to emails appearing blank. One common culprit is problematic HTML or CSS within the email template. Overly complex CSS, unsupported styles, or errors in HTML structure can cause email clients to fail at rendering the content, displaying a blank space instead. This is especially true for older or less compliant email clients that might not support modern web standards. Ensure your email HTML is clean, simple, and uses inline styling where possible.
Common rendering issues
HTML errors: Unclosed tags, incorrect nesting, or missing attributes can break rendering.
CSS complications: Use of CSS properties not widely supported by email clients, or external stylesheets that are blocked.
Image blocking: If the email content relies heavily on images and the recipient has image blocking enabled, the email might appear blank.
Merge field errors: Incorrect merge field coding (e.g., in HubSpot) can result in empty content if the data isn't pulled correctly.
Content filtering by ISPs, spam filters, or antivirus software is another significant factor. These systems are designed to protect users from malicious or unwanted emails. Sometimes, legitimate content can be mistakenly identified as suspicious, leading to its removal or suppression. This is a common reason why an email's body might be empty even if the sender's reputation is otherwise good. The filters might specifically target certain keywords, sender IPs on a blacklist, or certain HTML structures.
Finally, issues with email authentication protocols like SPF, DKIM, and DMARC can sometimes lead to content modification or outright rejection, though typically a full content strip to a blank email is less common for these unless there's an aggressive quarantine policy in place. For instance, a DMARC policy set to reject (p=reject) might cause a blank email to be delivered if the receiving server still accepts the message but strips its content due to authentication failure. You can learn more about how DMARC, SPF, and DKIM work.
Sender reputation and infrastructure impact
Your sender reputation plays a significant role in how ISPs handle your emails. A poor reputation can lead to emails being blocked, junked, or even having their content stripped. Factors contributing to a low reputation include high spam complaint rates, sending to invalid email addresses (which can lead to spam trap hits), and being listed on email blocklists (also known as blacklists). It's crucial to regularly monitor your domain and IP reputation using tools like Google Postmaster Tools and perform regular blocklist checks.
A robust email infrastructure is essential. This includes ensuring your mail servers are correctly configured, your IP addresses are warm (gradually sending more volume), and your sender domain is properly authenticated. If an email service provider (ESP) or sending platform is misconfigured, it can lead to various deliverability issues, including emails arriving blank. For instance, an error in how a platform handles merge fields could result in no content being inserted.
Positive reputation signals
High engagement: Consistent opens, clicks, and replies from recipients.
Low complaints: Few spam complaints relative to your sending volume.
Valid recipients: Minimal bounces and sending only to opted-in subscribers.
Proper authentication: Correct SPF, DKIM, and DMARC records in place.
Negative reputation signals
High bounces: Sending to invalid or non-existent email addresses.
Blocklist listings: Your IP or domain appears on common email blacklists.
Spam traps: Hitting dormant or abandoned email addresses used to identify spammers.
Low engagement: Consistent lack of opens or clicks from recipients.
If a specific ISP consistently shows blank emails, it's worth attempting to establish communication with their postmaster team. While often challenging, providing them with specific examples, sender details, and the raw email source can sometimes prompt them to investigate their filtering rules or provide insights into why content is being stripped. Maintaining good relations with ISPs is an ongoing aspect of email deliverability.
Advanced troubleshooting and prevention
Once you've diagnosed potential causes, it's time to implement solutions. If HTML/CSS rendering is the issue, simplify your email code. Avoid complex layouts, excessive use of external fonts or JavaScript, and always test your emails across a wide range of clients. Tools are available that provide previews of your email in various environments, helping you identify and fix rendering problems before they reach subscribers. Prioritize mobile responsiveness, as many users view emails on their phones.
Check your email content
Ensure your email content is not being accidentally suppressed or removed by your own sending platform or CMS. Sometimes, dynamic content blocks or merge tags can fail to populate, resulting in blank spaces. Regularly review content previews and send test emails to various addresses, including those from problematic ISPs.
Example of hidden preheader text in HTML emailhtml
<div style="display: none !important; mso-hide: all; height: 0; max-height: 0; overflow: hidden;">This is a preheader text.</div>
For content filtering issues, review your email content for anything that might trigger spam filters. This includes excessive links, unusual formatting, or spammy keywords. Ensure your email authentication (SPF, DKIM, DMARC) is correctly configured to prove your emails are legitimate and prevent content stripping by receiving servers. A properly configured DMARC policy helps ensure that content is not tampered with during transit. If your domain or IP is on a blocklist, seek delisting and address the underlying issues that led to the listing.
Maintaining a clean and engaged email list is vital. Regularly remove inactive subscribers and bounce addresses. This reduces the risk of hitting spam traps or generating high bounce rates, which can negatively impact your sender reputation and increase the likelihood of content being filtered. Implement double opt-in to ensure subscribers genuinely want to receive your emails, which reduces spam complaints and improves engagement.
Views from the trenches
Best practices
Always include a plain text version of your email alongside the HTML to ensure content always displays.
Routinely monitor your sender reputation and check for any blocklist (blacklist) listings.
Implement strong email authentication (SPF, DKIM, DMARC) for all sending domains.
Keep email HTML and CSS simple and compatible with various email clients and webmail services.
Conduct regular inbox placement tests to identify rendering issues across different providers.
Common pitfalls
Relying solely on forwarded emails for diagnosis, which often strips original content.
Ignoring recipient email client differences in rendering complex HTML/CSS.
Failing to monitor email bounce rates and spam complaints, which impact sender reputation.
Not segmenting lists or removing inactive subscribers, leading to lower engagement and potential filtering.
Overlooking errors in dynamic content or merge fields that result in empty content.
Expert tips
Use a tool to analyze your email's raw source for content integrity.
Test emails on actual devices and across various email clients to catch rendering glitches.
Communicate with affected subscribers to gather specific details about their email environment.
Consider engaging directly with problematic ISPs if issues persist for their subscribers.
Regularly audit your email sending practices against industry best standards.
Expert view
Expert from Email Geeks says they have seen thousands of inbox tests, including for Shaw.ca, and have not encountered widespread blank email issues. They recommend performing an inbox placement test to replicate the problem.
2024-01-05 - Email Geeks
Marketer view
Marketer from Email Geeks says that sometimes email applications might not show anything even if the email content isn't truly zero. They suggest verifying the raw source of the email.
2024-01-05 - Email Geeks
Ensuring successful email delivery
Resolving blank email issues requires a systematic approach, starting with accurate diagnosis and moving through technical and reputation-based solutions. By understanding the common causes, such as HTML/CSS rendering problems, aggressive content filtering, or issues with sender reputation, you can take targeted actions. The ultimate goal is to ensure your messages are not only delivered but also rendered as intended in your subscribers' inboxes. Continuous monitoring and adaptation to evolving email client behaviors and ISP requirements are key to long-term email deliverability success.
Outlook might display perfectly fine in 
Gmail's web interface. This distinction helps narrow down whether the issue is with the email content itself or with how a particular client renders it. Some clients have stricter rendering engines or security settings that might block or strip certain content.
