Why have email engagement rates dropped significantly for large broadcast sends since February?
Michael Ko
Co-founder & CEO, Suped
Published 29 Jul 2025
Updated 17 Aug 2025
7 min read
Over the past few months, particularly since February, many senders have observed a perplexing trend: a significant dip in email engagement rates, specifically for large broadcast campaigns. What makes this even more puzzling is that smaller, automated sends often maintain healthy engagement. This disparity points to underlying shifts in how mailbox providers assess and filter bulk email, making it crucial to understand the evolving landscape of email deliverability.
This recent change isn't a mere coincidence, but rather a direct consequence of updated sender requirements introduced by major mailbox providers. These changes, primarily from Gmail and Yahoo Mail (and consequently, AOL), place a heavier emphasis on sender authentication, low spam complaint rates, and, crucially, positive recipient engagement.
Understanding these shifts is essential for any sender looking to maintain strong inbox placement and engagement, especially when dealing with large volumes of email. The rules of the game have changed, and adapting your strategy is paramount to your success.
The core reason for these plummeting engagement rates lies in the tightened policies of major mailbox providers, particularly Gmail and Yahoo, which came into effect around February 2024. These providers are now much stricter on bulk senders, requiring robust email authentication and a clear demonstration of positive engagement from recipients. If these criteria aren't met, emails are increasingly being diverted to the spam folder, or even rejected entirely.
The distinction between large broadcast sends and automated messages is key here. Automated messages, such as transactional emails, password resets, or welcome sequences, typically have much higher engagement rates because they are expected and often triggered by a direct user action. Their inherent relevance leads to consistent positive interactions, which mailbox providers interpret as a strong indicator of legitimacy and desired content.
Conversely, large broadcast campaigns, especially those sent to less engaged segments or cold lists, are more susceptible to low engagement, spam complaints, and direct deletion without opening. Mailbox providers' algorithms are now heavily penalizing domains that exhibit these negative signals, leading to significant inbox placement issues. This is why you might see a sudden decline in your open rates across the board for certain campaigns, while automated flows remain unaffected.
Engagement metrics beyond open rates
With the rise of privacy features like Apple Mail Privacy Protection, the reliability of open rates as a standalone engagement metric has significantly diminished. Many emails are now automatically marked as opened even if the recipient hasn't actively viewed them. This means focusing solely on open rates can provide a misleading picture of your true audience engagement. As reported by VerticalResponse, open rates are dying, and it's time to shift focus.
Instead, it is imperative to look at deeper engagement metrics that reflect actual recipient interest and interaction. Clicks, conversions, replies, and even forwards are far more reliable indicators of how your audience is resonating with your content. ISPs are increasingly using these positive signals to determine your sender reputation and subsequent inbox placement.
Conversely, negative signals like spam complaints and unsubscribes carry significant weight. A high volume of these, even if your open rates appear superficially fine, can severely damage your deliverability. This is why you might experience drops in inbox placement despite seemingly stable open rates.
Traditional metrics
Open rate: Increasingly unreliable due to privacy features that auto-open emails, providing an inflated sense of engagement.
Bounce rate: Indicates issues with email list hygiene, leading to lower deliverability and potential blacklisting.
Conversion rate: Directly measures the effectiveness of your email in driving desired actions, like purchases or sign-ups.
Reply rate: Indicates genuine interest and engagement, showing recipients are willing to interact further.
Spam complaint rate: A critical negative signal that heavily influences your sender reputation.
Sender reputation and the role of authentication
Your sender reputation is the cornerstone of email deliverability. Mailbox providers assign a reputation score to your sending domain and IP address based on various factors, including your email authentication, spam complaint rates, and engagement. When large broadcast sends consistently show low engagement or high complaint rates, it signals to ISPs that your emails may not be desired, leading to a damaged reputation.
The enforcement of robust email authentication protocols like SPF, DKIM, and especially DMARC has become critical. These records help verify that your emails are legitimately coming from your domain, preventing spoofing and phishing. Without proper authentication, your emails are much more likely to be flagged as suspicious and sent to spam, regardless of your content.
Example DMARC record at enforcement of p=none (monitoring policy)DNS
Being placed on an email blacklist (or blocklist) is another significant consequence of poor sender reputation. These lists are used by ISPs to identify and block mail from suspicious sources. High complaint rates, sending to invalid addresses, or engaging in spam-like behavior can quickly land you on a blocklist (or blacklist), making it nearly impossible to reach the inbox. Understanding how email blacklists work is critical for every email marketer.
Important: blacklists can be very hard to get off
Once your domain or IP is listed on a major blocklist (or blacklist), recovering your sender reputation can be a lengthy and challenging process. It requires identifying the root cause, rectifying the issues, and then diligently requesting delisting. Prevention through consistent best practices is far more effective than trying to recover after the fact.
This highlights the intricate link between your sending practices, engagement metrics, and ultimate deliverability. Any misstep, particularly with large volume sends, can quickly unravel your efforts.
Strategies to improve engagement and deliverability
To combat declining engagement for large broadcast sends, a multi-faceted approach is required. First, rigorous list hygiene is non-negotiable. Regularly clean your lists to remove inactive subscribers, bounces, and spam traps. Sending to a smaller, more engaged audience will yield better results than blasting a massive, uncleaned list.
Second, personalize and segment your campaigns. Generic emails sent to everyone are unlikely to resonate. Tailor your content to specific audience segments based on their interests, past behavior, or demographics. This increases relevance and, in turn, engagement. You might also consider slowing down the send speed of your large campaigns to mimic the behavior of automated sends, which can sometimes bypass certain ISP fingerprinting algorithms.
Finally, proactively monitor your deliverability. Use tools to check your inbox placement, track your sender reputation across different mailbox providers, and keep a close eye on your spam complaint rates. Addressing issues promptly can prevent long-term damage to your sending infrastructure. Regularly performing an email deliverability test can help you stay ahead of potential problems.
Aspect
Best practice
Content
Ensure engaging and relevant content, avoiding spam triggers. Personalize emails for higher engagement and lower complaint rates.
List management
Regularly clean your email lists to remove inactive or invalid addresses, reducing bounces and spam trap hits.
Technical setup
Implement and maintain SPF, DKIM, and DMARC to ensure proper email authentication.
Monitoring
Continuously monitor your sender reputation and blacklist status to catch issues early.
Views from the trenches
Best practices
Implement stringent list hygiene practices to regularly remove unengaged subscribers and invalid email addresses.
Segment your audience precisely and tailor content to each segment to increase relevance and foster higher engagement rates.
Ensure proper email authentication with SPF, DKIM, and DMARC, moving towards enforcement policies like quarantine or reject.
Monitor your sender reputation and key deliverability metrics, including spam complaint rates and click-through rates, on an ongoing basis.
Common pitfalls
Relying solely on open rates as a measure of engagement due to privacy features that inflate these numbers.
Sending large broadcast emails at high speeds without warming up or adapting to mailbox provider throttling patterns.
Neglecting to clean inactive subscribers from your list, leading to lower overall engagement and increased spam complaints.
Ignoring DMARC reports, which provide crucial insights into authentication failures and potential spoofing attempts.
Expert tips
Consider slowing down the send speed of your large broadcast campaigns to mimic the consistent sending patterns of automated emails.
Focus on actionable engagement metrics like clicks, conversions, and replies rather than just opens to gauge true audience interest.
Break down deliverability issues by domain, especially for major providers like Gmail and Yahoo, to identify specific problems.
If your domain reputation has reset after authentication changes, be patient and consistent with good sending practices to rebuild it.
Marketer view
Marketer from Email Geeks says they have seen email engagement rates drop significantly, specifically for large broadcast sends since February, but automated messages maintain good rates.
2024-03-27 - Email Geeks
Expert view
Expert from Email Geeks says that if you implemented DKIM/DMARC around February or made changes, it could have reset your domain reputation at Gmail or Yahoo, and it might not have recovered yet.
2024-03-27 - Email Geeks
Adapting to the new email landscape
The significant drop in email engagement rates for large broadcast sends since February is not an isolated incident, but rather a clear signal of a shifting email landscape. Mailbox providers are increasingly prioritizing sender authenticity and genuine recipient engagement, making it harder for bulk senders to reach the inbox without a well-honed strategy. As inbox placement rates continue to collapse, adaptation is key.
Success in this new environment hinges on maintaining impeccable list hygiene, personalizing your content, ensuring strong email authentication, and continuously monitoring your sender reputation and key engagement metrics. By focusing on these areas, you can navigate the challenges and ensure your important messages continue to reach your audience's inboxes.
Gmail and 
Yahoo Mail (and consequently, AOL), place a heavier emphasis on sender authentication, low spam complaint rates, and, crucially, positive recipient engagement.
Gmail and 
Yahoo, which came into effect around February 2024. These providers are now much stricter on bulk senders, requiring robust email authentication and a clear demonstration of positive engagement from recipients. If these criteria aren't met, emails are increasingly being diverted to the spam folder, or even rejected entirely.
Apple Mail Privacy Protection, the reliability of open rates as a standalone engagement metric has significantly diminished. Many emails are now automatically marked as opened even if the recipient hasn't actively viewed them. This means focusing solely on open rates can provide a misleading picture of your true audience engagement. As reported by VerticalResponse, open rates are dying, and it's time to shift focus.
