What to know when your open rates decline

If your open rates have started to drop, it’s natural to question why, and it doesn’t always mean something is wrong with your content or strategy. Open rates are one of the most commonly monitored email metrics, but they’re also one of the most misunderstood. While it may feel like a direct reflection of your audience’s interest, the truth is more complicated.

Open rates are influenced by a mix of factors: your audience, your content, your sending habits, and even the evolving behaviors of mailbox providers like Gmail, Yahoo, and Apple. But beyond that, they’re based on technical signals, like the loading of a tracking pixel, that don’t always correlate to real human engagement. In some cases, an email can be opened and read but not tracked as an open at all. In others, an email can be marked as opened even though no one ever saw it.

This article will walk you through how opens are measured, why they’re imperfect, and what might be causing a decline in your open rates, even if your content or strategy hasn’t changed. We'll also give you practical tips for maintaining strong engagement and highlight what to watch out for.

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What counts as an open?

Open rates are measured using a small, invisible tracking pixel (typically 1x1). beehiiv embeds this pixel at the top of each email to help avoid clipping issues. When that image is loaded, the event is counted as an open. It’s a simple concept, but in practice, it’s anything but precise.

There are several ways an image can be loaded, and not all of them indicate that a real person opened and read your email. In fact, many opens are generated automatically, by mailbox providers, privacy tools, or spam filters, before the email even hits the inbox.

To make things more complicated, an email can be fully read without ever triggering that tracking pixel. If a recipient’s mail client blocks images by default, or if your subscriber is set up to view the email in plain text, no open will be recorded, even if the message was genuinely read.

The takeaway? Open rates are a directional metric at best. They offer a general sense of engagement, but they’re not a definitive measure of how many people are reading your emails.

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Why some emails don’t register as opened

If you're focused on why your open rates are falling, it's just as important to understand what isn't being tracked as an open, and why. Not all non-opens mean your audience is disengaged. In fact, many emails are delivered, seen, and even read without ever registering as ‘opened.

Here are the most common scenarios where an email might not be tracked as opened, even though it was delivered, and in some cases, even interacted with:

Delivery issues or spam placement

Some non-opens are the result of delivery problems or placement in folders where the message is unlikely to be seen.

• The email was never delivered due to a sender-side deliverability issue. This includes hard bounces (invalid addresses), soft bounces (mailbox full, temporary failure), or rejections related to the recipient’s mail server or domain reputation.
• The email couldn’t be delivered due to provider-side issues. In rare cases, a message may fail to reach the inbox due to shared IP blocking, throttling, or a temporary issue on beehiiv's infrastructure.
• The email was delivered to the spam or junk folder, where it went unnoticed.
• The email was delayed or deferred, and the recipient didn’t check their inbox after delivery.

Image blocking or suppression

In many cases, the email is opened, but image loading is disabled, so the tracking pixel is never triggered.

• The recipient’s mail client is configured to block images by default (common in older clients or enterprise environments).
• The recipient opened and read the email, but never chose to load images manually.
• The email was opened in a plain-text or preview pane that doesn't render images.
• Content filters or security tools removed or stripped the tracking pixel before delivery.

Privacy tools or network interference

Sometimes, privacy tools or network settings prevent image tracking, even if the recipient is actively engaging.

• Tools like Apple Mail Privacy Protection (MPP) or VPNs prevented the pixel from loading.
• The recipient opened the email while offline or in airplane mode, so images couldn’t be fetched from the server.
• The user uses a privacy relay that anonymizes image loading, but occasionally fails to complete the request.

Rendering Limitations

Technical quirks in how the email is constructed or rendered can also prevent open tracking.

•  The message was routed through an automated system (like a helpdesk or ticketing tool) that displayed the email without loading external images.

Just like with opens, non-opens aren’t always straightforward. Some reflect real disengagement, but others are caused by privacy tools, technical limitations, or mail client behavior outside your control. 

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Common reasons open rates decline

Even with strong content and a healthy list, open rates can decline for a variety of reasons. Some are tied to technical signals and infrastructure changes, while others relate to subscriber behavior or decisions made by mailbox providers. Here are the most common contributors: 

Deliverability and inbox placement

When emails are filtered to spam, or deferred, open rates naturally drop.

• Mailbox providers look at your sending history, complaint rates, bounce volume, and subscriber engagement to decide where your email should be placed.
• If negative signals accumulate (e.g., high spam complaints, poor engagement, or outdated lists), ISPs may begin throttling or junking your emails.
• Even a temporary dip in reputation can lead to lasting deliverability challenges if not addressed.

Changes to sending infrastructure

Any change to your sending fingerprint ( IP address, sending domain, and authentication configuration) can affect how mailbox providers treat your email.

• New domains or IPs must build reputation gradually (warming). Sending too much too soon can cause immediate filtering or deferrals.
• Switching between authenticated subdomains (e.g., from newsletter.brand.com to updates.brand.com) or sender names can disrupt reputation continuity.
• During these changes, Gmail and others may pause image prefetching as a security measure, which may lead to fewer recorded opens, even when emails are delivered and read.

Authentication and domain alignment issues

Mailbox providers rely heavily on authentication to verify that your email is legitimate and authorized.

• Missing or improperly configured SPF, DKIM, and DMARC records can reduce trust and increase the likelihood of spam folder placement.
• Gmail, Yahoo, and Microsoft now require strict authentication standards — failure to comply may lead to rejections or delivery delays. 

Link reputation and email content

Mailbox providers don’t just look at your domain, they also evaluate the content and links inside your emails.

• Linking to low-reputation or unverified domains (especially affiliate programs, ad trackers, or shady redirects) can trigger spam filters, even if your domain is reputable.
• Broken or unresolvable URLs, expired redirects, or domains with malware associations can result in hard blocks or silent deferrals.
• Content that feels overly promotional (e.g. ‘click here now,’ ‘limited time offer’) or formatting that uses excessive caps may also trip filters.

Audience fatigue and content relevance

Even with permissioned lists, engagement can fall if content becomes repetitive or irrelevant. 

• Over-sending can wear out your audience, while under-sending can lead to disinterest or forgotten subscriptions. 
• A lack of segmentation and personalization results in messages that feel generic, which drives down engagement over time.

Poor list hygiene and inactive subscribers

Continuing to email disengaged users sends negative signals to ISPs, and dilutes your open rate.

• Inactive subscribers, especially those who haven’t engaged in months, can drag down engagement rates and hurt your sender reputation.
• Purchased or third-party lists often contain poor quality addresses that bounce, complain, or never open. This is why beehiiv doesn’t allow them. 

• Failing to clean your list regularly can increase the risk of being filtered or blocked outright.

Privacy features and ISP tracking behavior

Mailbox providers like Apple, Google, and Microsoft continue to evolve how they handle tracking pixels and image loading, which can impact how opens are registered, even when filters are in place.

• At beehiiv, we filter out most auto-generated opens from privacy tools like Apple MPP and image prefetching systems. But when those systems change their behavior, such as prefetching less frequently, it can result in lower reported opens.
• As privacy features become more common, open rates may naturally trend lower across the industry, not because your engagement is worse, but because the tracking environment is becoming more restricted.

Seasonal trends and inbox saturation

Timing can play a major role, especially during high volume periods.

• During holidays, inboxes are flooded with promotional content, making it harder for your message to stand out.
• Mailbox providers tighten spam filters during high-risk periods to combat phishing and fraud, which increases the chances of false positives and lower inboxing rates.
• Even your most engaged readers may be overwhelmed or distracted during busy times of year.

Additional contributing factors

While less common than the issues above, these factors can still contribute to lower open rates, especially when layered on top of other deliverability or engagement challenges:

• Send time and time zone mismatch: Emails sent overnight or outside the subscriber’s time zone may get buried before they’re seen. Even small timing misalignments can lead to missed opens at scale.
• Forwarded or shared emails: When a subscriber forwards your email to a colleague or friend, that secondary recipient may read the message, but it won’t trigger your open tracking pixel. While this is positive engagement, it won’t be reflected in your open rate.
• Inherited domain reputation: If you’ve recently started sending from a domain with a prior history of abuse or spam, mailbox providers may carry that legacy forward, even if your current practices are clean. Rebuilding domain reputation can take time, even with authentication and warming.
• Weak subscriber memory or unclear opt-in flows: If a subscriber doesn’t clearly remember signing up (such as via a giveaway or co-registration) they may disengage silently without unsubscribing. Lack of brand recognition or vague signup language can erode engagement silently.

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Tips to improve or protect your open rates

While open rates aren’t a perfect metric, they’re still useful for tracking trends and identifying issues with engagement or deliverability. If you’ve seen a drop — or want to stay ahead of one — here are practical ways to strengthen performance. 

Maintain strong list hygiene

Healthy lists lead to healthier engagement and deliverability.

• Create automated journeys to regularly suppress or remove inactive subscribers, especially those who haven’t opened or clicked in several months.  
• Use a re-engagement campaign to win back your unengaged subscribers. 
• Enable double opt-in to improve list quality and intent. 
• Never use purchased, scraped, or co-registration lists; these are prohibited in beehiiv and harm your sender reputation. Be sure you are familiar with our Acceptable Use Policy (AUP). 
• Monitor bounce rates, unsubscribe rates, and spam complaints closely; high rates are a sign it’s time to clean your list or adjust your acquisition strategy.
• Set expectations clearly at the point of signup: who you are, what kind of content you'll send, and how often.
• If you’re acquiring subscribers through giveaways or partnerships, ensure those users are actively choosing to subscribe to your brand, not just checking a box.

Authenticate and align your sending domain

Authentication isn’t optional anymore, it’s essential.

• If you are using a custom domain to send your newsletter, ensure SPF, DKIM, and DMARC are properly configured and aligned by making sure your custom sending domain is set up correctly in the beehiiv app.  
• When using a new domain or IP, warm it up slowly; start with your most engaged subscribers first.

Optimize sending behavior and cadence

Your volume and frequency impact both engagement and inbox placement.

• Maintain a consistent sending pattern to avoid deliverability issues. 
• Avoid large or sudden spikes in volume, especially from a new IP or domain.

• Don’t over-send to unengaged recipients; suppress inactive segments or implement re-engagement campaigns before removing them entirely.

Segment and personalize your audience

The more relevant your content, the better your results.

• Create segments based on subscriber behavior (e.g., recent opens, past purchasers, signup source) and tailor your messaging accordingly.
• Don’t batch-and-blast. What works for one audience may cause another to disengage, or worse, complain your emails are spam.
• Use dynamic content, interest tags, or simple personalization to make your emails feel more targeted and valuable.

Improve subject lines and content quality

Your content sets the tone for engagement and filtering.

• Test subject lines to balance curiosity and clarity. 
• Avoid spammy language (e.g., excessive punctuation, all caps, deceptive urgency) that can trigger filters or reduce trust.
• Ensure your links are functional, relevant, and point to reputable destinations. Avoid link shorteners or redirection services unless necessary, and test before sending.

Send at the right time

Timing affects visibility more than most realize.

• Analyze your audience’s engagement patterns and adjust send times accordingly. 
• Consider using time zone-based sending if your list spans multiple regions.
• Be mindful of inbox competition during high-volume periods like holidays, where sending earlier in the day or avoiding sends at the top or bottom of the hour can improve performance.

Monitor infrastructure and domain reputation

Small technical missteps can lead to major deliverability issues.

• Keep an eye on blocklists, bounce logs, and spam complaint rates to identify problems early.
• Set up Google Postmaster Tools to monitor your performance. 
• Use a branded subdomain for sending (e.g., news.yourdomain.com) to help build isolated, positive sending reputation over time. Avoid using your root domain for every piece of mail. 
• Avoid sending from root domains or domains with a negative history.

Use engagement metrics beyond opens

Don’t rely on opens alone to judge success.

• Monitor your click-through rate (CTR), click-to-open rate (CTOR), and unsubscribe rate to get a more complete picture of performance.
• Watch for drops in engagement that align with content or infrastructure changes.
• Use opens directionally, not as your sole KPI or a financial metric.

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Understanding your open rates

At beehiiv, our goal is to give you open rate data you can trust. That means filtering out non-human interactions like bot activity, prefetching, and automated privacy opens — so your metrics reflect real subscriber behavior as accurately as possible.

But even with reliable tracking in place, your open rate is often ultimately shaped by your own sending practices. While beehiiv’s infrastructure plays a role, factors like subscriber acquisition, list maintenance, link quality, and proper authentication have a much bigger impact on engagement and inbox placement.

Open rates can surface useful trends, but they’re influenced by many overlapping factors and should always be viewed in a broader context. If you notice a decline in your open rates, take time to review your list quality, any recent changes, and your overall sending strategy.