Seeing your email open rates drop can be incredibly frustrating. It's a common issue that many email marketers face, and often, it's not due to a single cause but a combination of factors. The average open rate across industries has seen fluctuations, and recent changes in how mailbox providers handle emails have added complexity.
When open rates decline, it can signal deeper problems with your email program, from deliverability challenges to subscriber engagement issues. It's important to approach this by systematically investigating various potential culprits, from the technical backend to the content you're sending.
I'll walk you through the most common reasons why your email open rate might have decreased recently and what steps you can take to diagnose and fix the problem.
Technical setup and sender reputation
One of the most critical, yet often overlooked, reasons for a dip in open rates is your sender reputation. This is like a credit score for your email sending domain and IP address. Mailbox providers, such as Google and Yahoo, use this reputation to decide whether to deliver your emails to the inbox, the spam folder, or reject them entirely. A sudden decline usually indicates a hit to this reputation.
Technical email authentication protocols also play a massive role. SPF, DKIM, and DMARC are essential for proving your emails are legitimate and not spoofed. If these records are misconfigured or recently changed, it can drastically affect deliverability, pushing emails to spam, which naturally reduces your measured open rates. For example, if you migrated to a new email service provider (ESP) like Klaviyo, your DNS records might need updating.
Being listed on an email blacklist (or blocklist) is another critical factor. Many ESPs use these blacklists to filter out suspected spam. If your IP address or domain gets on a blocklist, your emails will likely be rejected or sent straight to the spam folder without reaching the inbox. This directly impacts your open rates, as the emails aren't even seen by recipients.
Ensuring proper authentication
Strong email authentication is key to ensuring your messages reach the inbox and build trust with mailbox providers. If your open rates have dipped, double-check these settings.
SPF: Ensure your SPF record includes all legitimate sending services and is within the 10-lookup limit.
DKIM: Verify your DKIM signatures are correctly configured and not failing, especially with services like Microsoft which can be particular.
DMARC: Implement a DMARC policy (even if it's p=none initially) and monitor reports to identify authentication failures.
Content and audience engagement
Even with perfect technical setup, your email content and how recipients engage with it profoundly impact open rates. If your subject lines are uninspiring or misleading, subscribers are less likely to click. The preheader text, the short snippet visible next to the subject line, is also crucial and often overlooked. If it doesn't complement the subject line effectively, it can hinder opens.
Relevance and personalization are more important than ever. Sending generic emails to your entire list can lead to subscriber fatigue and decreased engagement. Segmenting your audience and tailoring content to their specific interests, purchase history, or behavior can significantly improve open rates. Consider if you've recently changed your email template design, as this can sometimes introduce rendering issues or affect how your content is perceived.
Sending frequency also plays a role. If you start sending too many emails, you risk overwhelming your subscribers, leading to unsubscribes or, more commonly, disengagement and ignoring your emails. Conversely, not sending frequently enough can lead to subscribers forgetting who you are, making them less likely to open your messages.
Before
Subject Line: "Newsletter Update"
Content: Generic promotions to everyone on the list.
Frequency: Irregular or excessively frequent sends.
After
Subject Line: "[Name], Your weekly update on [Interest]"
Content: Segmented, personalized content relevant to recipient's behavior.
Frequency: Consistent, optimal sending schedule based on engagement.
If you are concerned about email click rates and open rates declining, consider the possibility that it is not a technical issue but rather an issue with the quality of your emails and audience engagement.
The health of your email list
The quality of your email list is fundamental to your open rates. Sending to an outdated, unengaged, or poorly sourced list can lead to significant drops. Inactive subscribers, for instance, are people who haven't opened or clicked your emails in a long time. Continuing to send to them signals to mailbox providers that your emails aren't valuable, harming your sender reputation.
Another major problem is hitting spam traps. These are email addresses specifically set up by ISPs and anti-spam organizations to catch spammers. Sending to a spam trap instantly damages your reputation and can lead to immediate blacklisting (blocklisting), severely impacting your deliverability and open rates. This often happens when lists are purchased or collected without proper opt-in consent.
List decay is also a natural process. Over time, email addresses become inactive, people change jobs, or simply lose interest. If you're not consistently refreshing your list with new, engaged subscribers, your overall engagement metrics, including open rates, will naturally decline.
Issue
Impact on Open Rates
Solution
Inactive subscribers
Lower sender reputation, fewer opens.
Implement re-engagement campaigns or remove unengaged contacts.
Spam traps
Immediate blacklisting (blocklisting) and deliverability failure.
Regularly clean your list; avoid purchased lists.
Lack of new contacts
Overall open rate decline due to natural list decay.
Focus on consistent, ethical list growth strategies.
ISP policies and privacy changes
The email landscape is constantly evolving, with mailbox providers regularly updating their filtering algorithms and privacy features. Recent changes, such as Apple's Mail Privacy Protection (MPP), have significantly skewed open rate metrics. MPP automatically loads images in emails, making it appear as if an email has been opened, even if the user hasn't seen it. While this can artificially inflate some open rates, it also means traditional open rate metrics are less reliable for gauging actual engagement.
Beyond privacy changes, Gmail and Yahoo's new sender requirements have introduced stricter rules for bulk senders regarding authentication, spam rates, and one-click unsubscribe options. Failing to comply with these can lead to messages being rejected or routed directly to spam, causing a genuine drop in your measurable open rates because the emails simply aren't reaching the primary inbox.
Your Email Service Provider (ESP) might also be adjusting how they calculate open rates. As mentioned in the Email Geeks Slack channel, some ESPs are becoming more sophisticated in filtering out non-human interactions (like bot opens or pre-fetching by ISPs) from their reported open metrics to provide more accurate data. This means your numbers might drop not because your emails are performing worse, but because the reporting has become more precise. I highly recommend checking Word to the Wise for more background.
Views from the trenches
Best practices
Regularly clean your email list by removing unengaged subscribers to improve overall deliverability and open rates.
Segment your audience based on behavior and interests to send more relevant and personalized content, increasing engagement.
Ensure all email authentication protocols (SPF, DKIM, DMARC) are correctly configured and regularly monitored for issues.
Common pitfalls
Ignoring inactive subscribers, which can signal to mailbox providers that your emails are not valued.
Sending generic content to your entire list, leading to subscriber fatigue and lower engagement.
Failing to adapt to new ISP requirements, which can result in emails being filtered to spam folders.
Expert tips
Use email deliverability testing tools to identify potential issues before sending campaigns.
Focus on engagement metrics beyond just open rates, such as click-through rates and conversions, for a holistic view.
Actively seek feedback from your subscribers to understand their preferences and improve content relevance.
Marketer view
A marketer from Email Geeks says that a sudden drop in open rates could be due to increased competition for the inbox, especially during peak seasons like Black Friday. If it's not ISP-specific, the issue might be related to the content being sent.
2024-11-25 - Email Geeks
Expert view
An expert from Email Geeks says that an ESP might have started filtering out "non-human interaction" image loads, which can reduce reported open metrics even if recipient behavior hasn't changed. They suggest asking the ESP about their open calculation methodology.
2024-11-25 - Email Geeks
Regaining control of your open rates
A decrease in email open rates is a signal to investigate, not to panic. By systematically reviewing your technical setup, assessing content relevance and engagement strategies, and maintaining a healthy email list, you can identify and address the root causes. It's crucial to understand that the email marketing landscape is dynamic, with continuous changes from mailbox providers and evolving privacy regulations.
Focus on building a strong sender reputation through consistent authentication and by providing genuine value to your subscribers. This not only helps your emails reach the inbox but also encourages opens and clicks, leading to better overall campaign performance. Remember, email deliverability is an ongoing process that requires continuous monitoring and adaptation.
Google and 
Yahoo, use this reputation to decide whether to deliver your emails to the inbox, the spam folder, or reject them entirely. A sudden decline usually indicates a hit to this reputation.
Microsoft which can be particular.
