Why did my email open rates drop after a template redesign, but click rates remained the same?
Matthew Whittaker
Co-founder & CTO, Suped
Published 25 Jul 2025
Updated 19 Aug 2025
6 min read
It can be perplexing when your email open rates suddenly plummet after a template redesign, especially when your click rates remain stable. This scenario points to a nuanced problem, often indicating that your emails are either not reaching the inbox at the same rate as before or that the way opens are being tracked has been impacted. Understanding the root cause requires a closer look at both technical aspects of your new template and how mailbox providers (ISPs) perceive changes to your sending patterns.
While a stable click rate suggests your content is still engaging, the drop in opens can hide significant deliverability issues. It's crucial to investigate whether your messages are landing in spam folders or if tracking mechanisms are failing due to the new design.
The complexities of email open rate tracking
Email open rates have become increasingly unreliable due to privacy changes. Traditionally, an email open is recorded when a tiny, invisible image (the tracking pixel) embedded in the email loads. If images are blocked by default in an email client or if a user has enabled privacy features, this pixel may not load, leading to an unrecorded open.
The impact of privacy on open rates
Many email clients, including Apple Mail, now offer privacy features like Mail Privacy Protection (MPP). This pre-fetches (loads) images, including tracking pixels, before a user even opens the email. While this might artificially inflate some open rates, it also makes it harder to distinguish genuine opens, rendering the metric less accurate. As VerticalResponse noted, open rates have become unreliable due to these privacy changes, making click-through rates a more accurate measure of email engagement. According to Constant Contact, a primary reason for dropped open rates is Apple's Mail Privacy Protection.
Conversely, a click is a direct user action. If someone clicks a link within your email, it means they saw the email and engaged with its content. When your click rates remain steady despite a drop in reported opens, it strongly suggests that the actual engagement with your content hasn't changed, but rather, the method of counting those engagements has been disrupted.
Technical factors related to template changes
A new email template, even if only HTML, can introduce various technical changes that impact how an email is rendered and tracked. One significant factor is the overall HTML payload size of the email. Many email clients, like Gmail, will clip messages that exceed a certain size threshold (typically around 102KB). If your new template is larger and causes clipping, and your tracking pixel is located at the bottom of the email, it might not load because the recipient hasn't clicked View entire message.
Old template characteristics
HTML size: Smaller, less likely to be clipped by email clients.
Tracking pixel placement: Potentially higher up in the email, ensuring it loads for more recipients.
New template characteristics
HTML size: Larger, increasing the risk of message clipping.
Tracking pixel placement: If placed at the bottom, it might not load if the message is clipped, skewing open rates down.
Even if you don't see the "message clipped" link, it's possible the tracking image is still not loading. This can happen if the email is technically over the size limit, but the clipping indicator isn't displayed for various reasons, or if image loading rules have changed for that specific template. Your email service provider (ESP), like SendGrid, usually controls where the tracking pixel is placed, but if you have custom code, you might have some influence. If your tracking image is on a different hostname from your main images, its loading might be independently affected by browser connection limits or caching rules, although this is less common for pixel-based tracking.
Impact on sender reputation and inbox placement
Mailbox providers maintain sophisticated filtering systems that analyze various signals to determine whether an email should land in the inbox, spam folder, or be rejected. A sudden change in your email template, even without changes to your sending infrastructure, can be perceived as a new 'fingerprint' by these filters. ISPs (Internet Service Providers) might temporarily treat the new template with more scrutiny, leading to a dip in inbox placement and, consequently, open rates.
This doesn't necessarily mean your domain reputation has tanked, but it suggests that the new template might be triggering certain filters that the old one didn't. This could be due to factors like new image-to-text ratios, different coding practices, or even new tracking URLs within the template. Ensuring strong email authentication (SPF, DKIM, DMARC) is always fundamental to good deliverability, as it builds trust with mailbox providers.
While your click rates remain the same, it implies that recipients who do receive and open the email are still finding the content valuable. The challenge is ensuring more of those emails reach the inbox in the first place. You should monitor your domain reputation with Google Postmaster Tools and perform blocklist checks (or blacklist checks) to rule out major issues.
Steps to diagnose and recover
To effectively diagnose why your email open rates dropped but click rates remained, it's essential to collect and analyze granular data. Don't jump to conclusions too quickly. Give your new template some time (at least a week or two) to gather sufficient data and allow ISP filters to adjust. However, if the drop is severe and sustained, immediate action is warranted. Always use a statistical significance calculator to confirm if the changes are truly significant or just random fluctuations.
Breaking down your email performance by recipient domain is invaluable. Since a large portion of your audience uses Gmail, analyzing your metrics specifically for Gmail recipients can confirm if they are the primary cause of the decline. Look for differences in open rates, spam placement, and rendering across various email clients and devices. This can reveal issues specific to how your new template displays or is handled in certain environments. You may also want to test deliverability with a new template.
Troubleshooting checklist
HTML size: Check if the new template exceeds 102KB. If so, optimize its code and image sizes.
Tracking pixel: Confirm the tracking pixel is loading, ideally placed higher in the email's HTML. Consult your ESP's documentation or support if you use a provider like SendGrid.
Spam folder placement: Use an email deliverability test to check if your emails are landing in spam folders.
Preheader text: Ensure your preheader text is still compelling and relevant, even if the subject line remains dynamic for your newsletter.
A/B testing: Conduct A/B tests with variations of your new template against the old one, or different versions of the new template to isolate the problematic elements.
Views from the trenches
Best practices
Always use a statistical significance calculator to confirm if observed changes are truly significant.
Break down email performance data by recipient email client (e.g., Gmail, Yahoo) to pinpoint specific impact areas.
Ensure your email's HTML size is optimized to prevent message clipping, especially for Gmail.
Verify the placement of your tracking pixel within the email HTML, ideally ensuring it loads high up.
Monitor your domain reputation and deliverability metrics closely after any template or sending changes.
Common pitfalls
Jumping to conclusions about open rate drops without sufficient data or statistical analysis.
Assuming stable click rates mean no underlying deliverability issues.
Neglecting the impact of email HTML size on message clipping and tracking pixel loading.
Not considering how subtle changes in an email template can affect ISP filtering.
Failing to adapt to evolving privacy features that impact open rate reporting.
Expert tips
ISPs prioritize delivering emails that their users genuinely want and engage with.
Any significant change to an email's structure or sending pattern can be seen as 'new' by ISPs, potentially triggering stricter scrutiny.
While open rates have limitations, they still provide a signal for initial engagement and inbox placement.
Focus on the holistic view of email engagement, including clicks, conversions, and unsubscribe rates, not just opens.
Continually test and optimize your email templates and sending practices to maintain deliverability.
Expert view
Expert from Email Geeks says those look like big changes, but it's important to use a statistical significance calculator against the raw numbers to check for true impact. Also, ensure reporting is done after a fixed point each time to compare engagement accurately.
2020-02-12 - Email Geeks
Expert view
Expert from Email Geeks says that if the click rate is unchanged, it's crucial to look at obvious factors first, such as whether the handler or URL of the image used for load tracking has changed, or if the tracking image is lost due to message truncation at Gmail because of message size.
2020-02-12 - Email Geeks
Moving forward with your email strategy
While the observed drop in open rates after a template redesign can be alarming, especially when click rates remain steady, it often points to issues with email rendering, tracking, or initial inbox placement rather than a fundamental decline in user interest. The stability of your click rate is a strong indicator that your content continues to resonate with your audience when it reaches them.
By systematically investigating potential technical issues like HTML size and tracking pixel placement, and by closely monitoring your deliverability across different email clients, you can identify and rectify the problem. Remember, a holistic view of your email performance, focusing on engagement metrics like clicks and conversions, provides a more accurate picture of your email program's health than open rates alone.
Apple Mail, now offer privacy features like Mail Privacy Protection (MPP). This pre-fetches (loads) images, including tracking pixels, before a user even opens the email. While this might artificially inflate some open rates, it also makes it harder to distinguish genuine opens, rendering the metric less accurate. As VerticalResponse noted, open rates have become unreliable due to these privacy changes, making click-through rates a more accurate measure of email engagement. According to Constant Contact, a primary reason for dropped open rates is Apple's Mail Privacy Protection.
Gmail, will clip messages that exceed a certain size threshold (typically around 102KB). If your new template is larger and causes clipping, and your tracking pixel is located at the bottom of the email, it might not load because the recipient hasn't clicked View entire message.
SendGrid, usually controls where the tracking pixel is placed, but if you have custom code, you might have some influence. If your tracking image is on a different hostname from your main images, its loading might be independently affected by browser connection limits or caching rules, although this is less common for pixel-based tracking.
