How to accurately measure email open rates without relying on image pixels or clicks?
Matthew Whittaker
Co-founder & CTO, Suped
Published 19 Apr 2025
Updated 10 Oct 2025
8 min read
The traditional email open rate, often measured by tiny, invisible image pixels, has become increasingly unreliable. With the advent of privacy features like Apple Mail Privacy Protection (MPP) and the growing sophistication of spam filters that pre-fetch images, marketers are left with inflated or inaccurate numbers. This makes it challenging to truly understand how well an email campaign is performing and if recipients are genuinely engaging with the content. We need to move beyond these outdated methods to gain meaningful insights into email performance. It raises the question of whether email tracking is dead and if marketers should stop using open rates altogether.
Relying solely on image pixels or clicks for open rate metrics no longer paints an accurate picture of audience engagement. It's crucial to explore alternative methods that provide a more realistic assessment of how your emails are resonating with subscribers. This shift requires a deeper understanding of deliverability and user behavior, focusing on metrics that truly reflect interaction rather than mere technical events.
The limitations of traditional open rate tracking
The standard practice for tracking email opens involves embedding a small, often 1x1 pixel, transparent image within the email's HTML. When a recipient opens the email and their email client loads images, this pixel is requested from a server, registering an "open." This method has long been a cornerstone of email marketing analytics, despite its inherent limitations.
However, the accuracy of this method has been significantly compromised. With features such as Apple Mail Privacy Protection (MPP), which pre-fetches and caches images regardless of whether a user actually opens the email, pixel-based open rates can be artificially inflated. This means a reported "open" doesn't necessarily correspond to human interaction. For more details, explore how email image caching affects open rates. Similarly, some email clients and security software block images by default, leading to underreported opens.
Beyond privacy features, spam filters and bot activity can also trigger pixel loads without any human involvement. This further distorts the data, making it difficult for marketers to distinguish between genuine interest and automated actions. Understanding these nuances is key to recognizing that a high open rate, by itself, may not reflect true engagement.
The challenge of inaccurate open rates
Traditional open rate metrics are fundamentally flawed due to various technical and privacy-related factors. This affects the overall perception of email campaign success.
Apple Mail Privacy Protection (MPP): Pre-fetches images, inflating perceived opens without user interaction. It complicates estimating real open rates with MPP.
Image Blocking: Users or email clients may disable image loading, leading to undercounted opens.
To genuinely measure email engagement, we must look beyond the pixel and focus on active user responses. Metrics that require a deliberate action from the recipient provide a far more reliable indicator of interest. This shift helps circumvent the inaccuracies introduced by automated image loading and privacy features.
The click-through rate (CTR) is a prime example. A click on a link within your email indicates an active decision by the recipient to engage further with your content. While this doesn't capture every open, it provides a much stronger signal of intent than an automatically loaded image. Pairing this with Google Analytics or other web analytics tools can give deeper insights into post-click behavior.
Beyond clicks, consider tracking direct replies, conversions, or sign-ups attributed to specific email campaigns. If your email prompts a purchase, a form submission, or a download, these are definitive proof of engagement. These actions provide undeniable evidence that your message was not only received but also acted upon, offering a tangible measure of your email's effectiveness. We need to be able to accurately measure email engagement to improve our campaigns.
Traditional pixel tracking
Mechanism: Embeds a 1x1 invisible image that loads upon opening. More about tracking pixels in email.
Mechanism: Requires user clicks, replies, or conversions.
Accuracy: Higher, reflecting direct user intent.
Metric type: Active, indicative of genuine engagement.
Leveraging DMARC for deliverability insights
While DMARC doesn't directly measure email opens, it provides foundational insights into email deliverability and authentication, which are critical prerequisites for any email to even have the chance of being opened. By ensuring your emails are properly authenticated, you significantly increase their likelihood of reaching the inbox, rather than being flagged as spam or rejected.
DMARC reports, easily accessible through a platform like Suped DMARC monitoring, offer valuable data on email authentication status (SPF and DKIM). These reports reveal if your emails are aligning with your domain's policy and if any legitimate emails are failing authentication. A well-configured DMARC policy helps protect your domain from spoofing and phishing, building trust with recipient servers.
By actively monitoring DMARC, you can ensure your email infrastructure is healthy, which indirectly supports genuine engagement. Although it doesn't quantify opens, it ensures your messages arrive where they can be seen. This forms a crucial part of an overall deliverability strategy, which influences every other metric. Understanding the basics of DMARC, SPF, and DKIM is a must.
Adopting a holistic approach to email performance means integrating various metrics that collectively paint a clearer picture of your audience's interaction. Instead of fixating on a single, flawed metric like pixel-based open rates, we should consider a blend of explicit and implicit signals.
Beyond clicks and conversions, think about website visits originating from email campaigns, time spent on landing pages, or even direct searches for your brand following an email send. These are powerful indicators of engagement. A/B testing different subject lines, content, and calls to action, without necessarily tracking pixels, can help you understand what truly resonates with your audience and drives action.
Ultimately, the goal is to provide value that naturally encourages interaction. Strong, clear calls to action, compelling content, and relevant offers will always drive more meaningful engagement than trying to track every pixel. This focus on value will lead to more tangible results, which can be measured through more reliable, action-based metrics. Discover the best alternative metrics to email open rates.
Metric
Description
Reliability
Pixel-based opens
Loads a hidden image when an email is opened.
Low (inflated by MPP, bots).
Click-through rate
Number of unique clicks on links within the email.
High (requires active user intent).
Conversion rate
Percentage of recipients completing a desired action.
Very high (direct impact on business goals).
Reply rate
Number of direct replies to an email.
High (indicates strong personal engagement).
Website engagement
Behavior on your site after clicking from an email.
High (shows interest beyond the email).
Embracing a new era of email measurement
The era of relying solely on pixel-based open rates for email performance measurement is behind us. The increasing prevalence of privacy features and sophisticated spam filters makes these metrics unreliable and often misleading. To accurately gauge the effectiveness of your email campaigns, it's essential to pivot towards more robust, action-oriented metrics.
By focusing on metrics like click-through rates, conversions, and direct replies, you gain a clearer understanding of genuine subscriber engagement. These actions require conscious effort from recipients, providing a more truthful reflection of their interest and interaction with your content. Moreover, a solid DMARC implementation ensures your emails are authenticated and delivered effectively, setting the stage for any engagement to occur.
Embrace a holistic view of your email program, prioritizing deliverability, valuable content, and clear calls to action. This comprehensive approach will not only provide more accurate performance insights but also foster stronger, more meaningful connections with your audience. Remember that how you use opens as a metric for email marketing should reflect these changes.
Views from the trenches
Best practices
Always encourage some form of engagement within emails, such as a clear call to action or a prompt to visit online resources.
Prioritize email authentication protocols like DMARC, SPF, and DKIM to improve deliverability and build recipient trust.
Regularly review click-through rates and conversion metrics, as these provide more accurate insights into active user engagement.
Consider segmenting your audience and A/B testing different approaches to content and calls to action to see what drives the most interaction.
Common pitfalls
Over-reliance on pixel-based open rates, leading to inflated or inaccurate performance assessments.
Sending emails with no clear call to action, making it difficult to measure genuine user interest or interaction.
Neglecting email authentication, which can negatively impact deliverability and the chance of emails being seen.
Ignoring the impact of Apple Mail Privacy Protection and other privacy features on traditional open rate metrics.
Expert tips
Focus on the value proposition of your email content to encourage direct interaction, making tracking less about passive opens and more about active engagement.
Use UTM parameters in your links to track website traffic and conversions originating from specific email campaigns, offering deeper analytics.
Experiment with unique coupon codes or personalized offers within emails to attribute sales and actions back to specific campaigns.
Regularly clean your email lists to remove inactive subscribers, which can improve overall engagement rates and deliverability.
Marketer view
Marketer from Email Geeks says that while clicks can be equated to opens, it is crucial to first filter out clicks originating from spam filters for accurate analysis.
2018-03-12 - Email Geeks
Marketer view
Marketer from Email Geeks says that a truly realistic open rate would require a more reliable metric, especially for emails without links or when recipients do not click.
2018-03-12 - Email Geeks
Key takeaways for accurate email measurement
For accurate email marketing insights, marketers must shift focus from pixel-based open rates to more reliable metrics. Understanding how to calculate email open rate is still useful, but the context has changed.The email open rate formula of (opens / emails sent) * 100 is less meaningful with inflated data. Prioritizing engagement metrics such as click-throughs, replies, and conversions provides a truer measure of audience interaction and campaign effectiveness. Implementing strong email authentication through DMARC is also key to ensuring messages reach their intended recipients, which is the first step toward any form of engagement.
Apple Mail Privacy Protection (MPP): Pre-fetches images, inflating perceived opens without user interaction. It complicates estimating real open rates with MPP.
