Why am I seeing open rate drops specifically in California?
Matthew Whittaker
Co-founder & CTO, Suped
Published 30 Jun 2025
Updated 19 Aug 2025
7 min read
It can be perplexing when your email open rates suddenly drop, especially when the decline seems concentrated in a specific geographic region like California. Many marketers experience this, and it often points to shifts in how email clients handle privacy and data, rather than a direct problem with your audience in that state. This phenomenon is frequently tied to how email opens are tracked and where the servers performing these actions are located.
Understanding these underlying mechanisms is crucial to accurately interpreting your email performance. The traditional 'open rate' metric has become less reliable due to recent privacy enhancements. This means a drop isn't necessarily a sign of disengagement or a problem with your emails, but rather a change in how opens are being reported.
For those seeking to understand a general drop in engagement, we have resources like what causes a sudden drop in email open rates. However, a localized drop, specifically in California, points to a very particular set of factors that need to be considered.
The impact of Apple mail privacy protection (MPP)
The primary suspect for open rate drops concentrated in California is Apple's Mail Privacy Protection (MPP). Introduced to give users more control over their data, MPP works by pre-loading email content, including tracking pixels, through proxy servers. This process marks an email as opened regardless of whether the recipient actually viewed it.
A key aspect of MPP's implementation is that these proxy servers are often located in specific geographical regions, with a significant concentration in California, where Apple's headquarters are. When your email service provider (ESP) or tracking system registers an open, it attributes that open to the location of the proxy server, not the user's actual physical location. This can artificially inflate open rates from California addresses or, conversely, mask genuine engagement.
The impact of MPP often means that what appears as an open from California may simply be an automated pre-fetch. If you've recently experienced a decrease in open rates specifically in this region, it's highly likely a reflection of your email service provider (ESP) or analytics platform adjusting its methodology to account for MPP, or simply a shift in how those proxy opens are being reported over time. This means you might be seeing a more accurate reflection of actual engagement, or simply a reporting adjustment.
Geolocation anomalies and Google's pre-fetching
Similar to Apple, Google also employs systems that can pre-fetch images and tracking pixels within emails, often from their own servers. Since a substantial portion of Google's infrastructure and headquarters are in California, these pre-fetches can be misattributed to the state by geolocation databases. This means an open might appear to come from California, even if the actual recipient is in another state or country.
This leads to what's often referred to as phantom opens or proxy opens, where the tracking pixel is loaded by the email provider's server, not the end-user. If your email service provider relies heavily on IP-based geolocation for reporting opens, you might see fluctuations that reflect changes in how Google's (or other major ISPs') servers pre-fetch content, rather than actual user behavior.
This issue is not exclusive to California. Similar pre-fetching behavior from Yahoo and AOL mail can also lead to skewed open rates, potentially pointing to locations where their servers are predominantly based. Therefore, a localized drop might be an indication that your email platform is getting better at filtering out these proxy opens, or that the volume of such opens from specific IP ranges has changed.
Troubleshooting localized open rate drops
Assessing the real impact
When you observe a drop in open rates localized to California, the first step is to check if it's genuinely affecting your engagement, or if it's purely a reporting anomaly. Focus on metrics that indicate true user interaction, such as click-through rates (CTR). If your CTR for California remains stable or has not seen a proportional drop, then the open rate decline is likely due to the privacy features mentioned, not a problem with your campaign or audience.
Also, investigate your domain reputation with major mailbox providers. If your emails are suddenly landing in spam folders for California recipients, this could also explain a drop in genuine opens. Tools like Google Postmaster Tools can provide insights into your Gmail deliverability and spam rate, which are particularly relevant given Google's California presence.
Consider if there have been any recent changes to your email infrastructure, sending volume, or list segmentation that might correlate with the drop. Even slight adjustments can influence how mailbox providers treat your emails. If you're seeing a sudden drop in open rates in a specific region, it is essential to look at the broader context of your deliverability metrics.
What to examine
Click-through rate (CTR): This is a more reliable indicator of actual engagement than open rates alone, especially with privacy changes. If your CTR is stable, the open rate drop might be a reporting artifact.
Recipient domain analysis: Break down your open rates by domain (e.g., Gmail, Yahoo, Outlook) to see if the drop is concentrated on specific providers. This can help pinpoint the cause.
Spam complaints and bounces: An increase in these metrics, even if opens remain high, signals deliverability issues. This is especially important for why your emails might be going to spam.
Maintaining accurate email performance insights
With the evolving landscape of email privacy, relying solely on open rates can be misleading. It's more beneficial to adopt a holistic approach to measuring email performance. Look beyond opens to engagement metrics like CTR, conversion rates, and the value derived from your email campaigns.
Ensure your email list hygiene is top-notch. Regularly remove inactive subscribers and unengaged contacts. This not only improves your deliverability by signaling to mailbox providers that you send to an engaged audience, but also gives you a more accurate picture of your true audience engagement. For example, Microsoft stresses the importance of list hygiene to diagnose engagement drops.
Lastly, stay informed about changes from major mailbox providers like Google and Yahoo. Their updates to sender requirements and privacy features can directly impact how your open rates are reported, regardless of your audience's location.
Views from the trenches
Best practices
Actively monitor your click-through rates (CTR) as a primary engagement metric, as open rates are becoming less reliable due to privacy features.
Segment your email performance data by recipient domain (e.g., Gmail, Apple Mail) to identify specific areas where deliverability or reporting might be impacting opens.
Maintain a clean and engaged email list by regularly removing inactive subscribers and managing unengaged contacts to improve overall deliverability and data accuracy.
Common pitfalls
Over-reliance on open rates for campaign success measurement, especially for segments affected by Mail Privacy Protection (MPP) and similar pre-fetching behaviors.
Misinterpreting a drop in reported open rates from specific regions, like California, as a sign of audience disengagement rather than a technical reporting change.
Failing to adapt email tracking and analytics strategies to account for modern privacy features, leading to skewed performance insights and misguided optimization efforts.
Expert tips
Use email deliverability tests to verify inbox placement across different ISPs and identify any filtering issues that could genuinely impact engagement.
Leverage DMARC reports to gain deeper insights into email authentication, delivery, and potential issues that might affect how providers handle your mail.
Focus on content relevance and personalization to drive actual engagement and clicks, which are more reliable indicators of campaign effectiveness.
Expert view
Expert from Email Geeks says a drop in California open rates might indicate delivery problems at Google, affecting their pixel pre-fetching.
2022-07-30 - Email Geeks
Expert view
Expert from Email Geeks says Google's headquarters are in California, so geolocation databases might inaccurately attribute pre-fetched opens to California IPs.
2022-07-30 - Email Geeks
Navigating the new normal for email metrics
Localized open rate drops, particularly in California, are often symptoms of broader shifts in email privacy and tracking rather than a direct issue with your audience. Apple Mail Privacy Protection and Google's pre-fetching behaviors are significant contributors to these reporting anomalies, as they can cause opens to be registered from proxy servers located in specific regions.
To accurately assess your email program's health, shift your focus from raw open rates to more reliable engagement metrics like click-through rates. Investigate your deliverability and sender reputation, and consider segmenting your audience and performance data by domain to gain clearer insights. By understanding these modern email dynamics, you can make informed decisions and optimize your campaigns effectively, ensuring your messages resonate with your actual audience.
