Why are open rates increasing and what does it mean for email marketing analysis?
Matthew Whittaker
Co-founder & CTO, Suped
Published 21 Jun 2025
Updated 17 Aug 2025
8 min read
Recently, many email marketers and deliverability professionals have observed a significant increase in their email open rates. This phenomenon, while seemingly positive, raises questions about the true accuracy and implications for email marketing analysis. We've seen discussions across various forums, with some noting a surge in opens, particularly from certain user agents like Mozilla/5.0 (Windows NT 5.1; rv:11.0) Gecko Firefox/11.0 (via ggpht.com GoogleImageProxy).
This uptick isn't necessarily a sign of suddenly improved campaign performance or heightened subscriber engagement. Instead, it often points to changes in how Internet Service Providers (ISPs) and email clients handle emails, especially regarding image prefetching. Understanding these technical shifts is crucial for accurately assessing campaign effectiveness and avoiding misinterpretations of your data.
While open rates have always been considered an imperfect metric, these recent changes further complicate their reliability. It's important to investigate the underlying reasons for such increases, rather than simply celebrating them as pure success. This article will delve into why these increases are occurring and what they mean for the future of email marketing analysis.
The shifting landscape of email opens
The primary driver behind the recent surge in email open rates is image prefetching by major mailbox providers. Companies like Google, Yahoo, and Apple have implemented or expanded features that automatically download images within an email as soon as it hits the inbox, regardless of whether the recipient actually opens it. This is often done to enhance user privacy, as it masks the user's IP address and other data from senders.
This prefetching mechanism triggers the tracking pixel embedded in marketing emails, which in turn registers an open even if the email remains unread. The result is an inflated open rate, where a significant portion of opens aren't genuine engagements but rather automated actions by the recipient's email service. We've seen a spike in Gmail open rates particularly attributable to this behavior.
Furthermore, business filters and security solutions often pre-scan emails for malicious content or spam, which also involves loading images and clicking links within the email. This contributes to the same phenomenon, registering an open (and sometimes even a click) without any human interaction. If your emails are consistently landing in the inbox, this prefetching behavior is more likely to occur, thus increasing your reported open rates.
Decoding the data: what an increased open rate means
The core issue is that what constitutes an open is no longer a clear indicator of a recipient's conscious engagement. This doesn't mean open rates are entirely irrelevant, but their interpretation must evolve. An increased open rate, especially if driven by prefetching, primarily confirms that your email successfully reached the recipient's inbox and that their mailbox is actively being checked.
This distinction is critical. If your open rates have soared, it might simply indicate improved deliverability, moving your mail from spam folders or promotion tabs into the primary inbox. While this is a positive outcome for deliverability, it masks the actual human interaction with your content. You can read more about why email open rates are still relevant for marketers in this helpful article.
The challenge for email marketing analysis is to look beyond the superficial numbers. Traditional Key Performance Indicators (KPIs) like open rates, which have long been central to campaign evaluation, now provide a less precise picture of engagement. This necessitates a shift in focus towards metrics that more reliably reflect active user interest.
Here's a comparison of how to interpret opens in the past versus today:
Past interpretation of opens
Direct engagement: A reliable indicator that a recipient consciously opened and viewed the email.
Subject line effectiveness: Primarily used to gauge how compelling the subject line was in enticing recipients.
Audience interest: A strong signal of overall audience interest and connection to your brand.
Current interpretation of opens
Deliverability signal: Primarily indicates successful inbox placement and active mailboxes, but not necessarily human engagement.
Masked engagement: Prefetching (like Apple's Mail Privacy Protection) inflates figures, making true engagement harder to discern.
Supporting metric: Best used as an aggregate trending metric, supporting other engagement indicators.
This means that while an increase in open rates might suggest your emails are reaching the inbox effectively, it doesn't automatically imply that more people are reading your content. Marketers need to adapt their analytical approaches to gain truly actionable insights.
Adjusting your email marketing analysis
Given the changing nature of email open data, it's essential to adjust your email marketing analysis to focus on more reliable engagement metrics. While open rates still indicate successful delivery, they are no longer the sole, or even primary, metric for measuring audience interest. This is particularly true since the widespread adoption of Mail Privacy Protection by providers like Apple, which automatically prefetches images to mask user activity.
Instead, prioritize metrics that directly reflect user intent and interaction with your content. These include:
Click-through rate (CTR): Measures how many recipients clicked a link within your email. This is a strong indicator of engagement.
Click-to-open rate (CTOR): Provides insight into how engaging your content is after the email has been 'opened' (or prefetched). This metric should be seen as a true indicator of engagement with the content itself, not just that it was delivered to the inbox.
Conversions: The ultimate measure of success, tracking actions like purchases, sign-ups, or downloads that result from your email campaigns.
Reply rates: For personal or conversational emails, replies are a direct sign of engagement and interest.
While you might see an increase in raw open numbers, a disproportionate increase without a corresponding rise in other engagement metrics could signal that these are largely prefetching 'opens'. It's important to analyze these numbers in conjunction with your deliverability data, such as your inbox placement rate. If your deliverability has improved, you might naturally see more prefetching activity. Conversely, a sudden drop in email open rates could indicate a deliverability issue. You can learn more about what to check if this happens.
Adapting your strategy for modern email marketing
Given the dynamic nature of email metrics, adapting your strategy to account for prefetching and other automated actions is crucial. It’s no longer about chasing the highest open rate, but understanding the true engagement behind the numbers.
A proactive approach to deliverability, combined with a refined analytical framework, will ensure your email marketing efforts remain effective. Regularly monitor your DMARC reports and blacklist status to ensure your emails are consistently reaching the inbox. This forms the foundation upon which true engagement can be built and accurately measured.
Focus on enhancing content relevance, improving sender reputation, and implementing robust email authentication. These factors contribute to better inbox placement and, consequently, more meaningful interactions, rather than just higher numerical opens. When your emails consistently land in the inbox, it’s more likely that automated systems will prefetch, leading to a rise in reported open rates. This indicates good deliverability, but not necessarily human interaction. Improving your deliverability is a continuous process that involves technical configuration and content strategy.
The key is to understand that inflated open rates due to prefetching are a side effect of good deliverability and privacy measures. While they complicate traditional analysis, they underscore the importance of getting your emails to the inbox. Once there, your focus shifts to compelling content and clear calls to action that drive clicks and conversions.
Views from the trenches
Best practices
Actively segment your email list based on engagement to send targeted content to active subscribers.
Regularly clean your email list to remove inactive or unengaged contacts.
Use A/B testing for subject lines and preview text to see what truly resonates with your audience.
Monitor core metrics like click-through rates and conversions, as these indicate genuine interest.
Ensure strong authentication protocols like DMARC, SPF, and DKIM are properly configured.
Common pitfalls
Relying solely on open rates as a primary KPI for campaign success, ignoring other engagement metrics.
Not segmenting email lists, leading to generic content for diverse audiences.
Ignoring list hygiene, which can lead to lower engagement over time.
Failing to track beyond clicks, missing out on valuable conversion data.
Not regularly checking your domain's reputation or blocklist status.
Expert tips
If open rates increase dramatically, investigate the underlying cause, especially prefetching patterns.
Focus on the trend of your open rates rather than individual campaign spikes or dips.
Analyze engagement alongside deliverability, as high open rates can signal good inbox placement.
Prioritize list quality over quantity to ensure a more engaged subscriber base.
Understand that some opens are automated, and shift your focus to human-driven metrics.
Expert view
Expert from Email Geeks says that all the recent open data is garbage. You can categorize it as you like, but it is important to understand what the underlying data you are using means, rather than just using the categories.
2023-10-19 - Email Geeks
Marketer view
Marketer from Email Geeks says that Google, Yahoo, and Apple all prefetch images. This indicates that the mail ended up in the recipient's inbox and that the mailbox is regularly checked, and that is all.
2023-10-19 - Email Geeks
Navigating the new reality of email metrics
The recent increase in email open rates, driven largely by image prefetching and privacy features, marks a significant shift in email marketing analysis. While seemingly beneficial, these inflated numbers can be misleading if not understood in context. They primarily signal successful inbox placement and active mailboxes, rather than a direct increase in human engagement.
For marketers, this means moving beyond open rates as the sole measure of success. A more holistic view involves prioritizing metrics like click-through rates, click-to-open rates, conversions, and replies. These provide a more accurate picture of how recipients are actually interacting with your content and taking desired actions.
Ultimately, the goal remains the same: to deliver valuable, engaging content to an interested audience. Adapting your analytical approach and focusing on true engagement metrics will ensure your email marketing strategy remains effective in this evolving landscape.
Google, 
Yahoo, and 
Apple have implemented or expanded features that automatically download images within an email as soon as it hits the inbox, regardless of whether the recipient actually opens it. This is often done to enhance user privacy, as it masks the user's IP address and other data from senders.
