Why have email open rates dropped suddenly even though inbox placement is fine?

Summary

A sudden drop in email open rates, despite successful inbox placement, is often a multifaceted issue involving factors beyond just deliverability. These factors span technical aspects (email clipping, one-click unsubscribe implementation), subscriber engagement (list fatigue, content relevancy, sending frequency), domain and sender reputation, external influences (Apple's MPP, seasonal trends), and inbox provider filtering (graymail suppression). A holistic approach involving technical checks, content optimization, list management, reputation monitoring, and adaptation to privacy changes is essential for diagnosing and addressing the problem.

Key findings

  • MPP Skews Open Rates: Apple's Mail Privacy Protection inflates open rates, masking true engagement.
  • Content Relevance Matters: Irrelevant content leads to subscriber disengagement, impacting open rates even with good inbox placement.
  • List Fatigue Reduces Engagement: Over-mailing or irrelevant content causes list fatigue, leading to lower open rates.
  • Segmentation Enhances Relevance: Lack of audience segmentation results in irrelevant messaging and lower open rates.
  • Frequency Affects Engagement: High sending frequency without valuable content causes subscriber burnout and reduced opens.
  • Technical Factors Intervene: Email clipping and improper one-click unsubscribe setup negatively influence open rates.
  • External Forces Impact Opens: Holidays and seasonal trends can affect email open rates independent of deliverability.
  • Google's Unsubscribe Preference: Google prioritizes proper one-click unsubscribe implementation; non-compliance can hurt deliverability.
  • Graymail Suppression Hides Emails: Inboxes may filter emails as 'graymail,' hiding them from the primary inbox due to low engagement.
  • Reputation Affects Visibility: Declining domain reputation can lead to throttling or placement in less prominent inbox tabs.
  • Lack of Recorded Spam Complaints: Spam complaints from spam folders do not show in postmaster tools.

Key considerations

  • Monitor Domain Reputation: Consistently monitor domain reputation using tools like Google Postmaster Tools and Microsoft SNDS.
  • Optimize Sending Frequency: Optimize sending frequency to avoid overwhelming subscribers with too many emails.
  • Check One-Click Unsubscribe: Ensure proper implementation of one-click unsubscribe, paying close attention to HTTPS and `List-Unsubscribe-Post`.
  • Test Email Rendering: Test email rendering across devices and email clients to ensure proper display and functionality.
  • Review Postmaster Tools Data: Analyze recipient domain open and click data to identify issues with specific providers.
  • Refine Content and Strategy: Actively collect and analyze subscriber feedback to refine content and campaign strategy.
  • Segment Email List: Segment email lists based on subscriber demographics, behavior, and engagement to target messaging effectively.
  • Optimize Subject Lines: Monitor and A/B test subject lines to maximize open rates and engagement.
  • Avoid Email Clipping: Avoid email clipping by keeping total size under 102kb.
  • Adapt to MPP: Account for MPP skewed numbers by focusing on other performance indicators like clicks.

What email marketers say
12Marketer opinions

A sudden drop in email open rates despite inbox placement can stem from various factors beyond deliverability. These include technical issues like email clipping or improper one-click unsubscribe setup, subscriber-related problems such as list fatigue or irrelevant content, external factors like Apple's MPP or seasonal trends, and sending strategy weaknesses like lack of segmentation or high frequency. Analyzing these areas provides actionable insights for improving engagement.

Key opinions

  • MPP Impact: Apple's Mail Privacy Protection inflates open rates, masking actual engagement. A drop after MPP implementation may be a more accurate reflection of opens.
  • Content Relevancy: Subscribers stop opening emails if the content is no longer relevant. Analyze behavior and adjust content strategy.
  • List Fatigue: Decreased open rates can stem from list fatigue. Subscribers receiving too many emails disengage.
  • Segmentation: Lack of segmentation leads to decreased engagement. Send relevant content based on subscriber interests.
  • Sending Frequency: Increased sending frequency without valuable content can cause subscriber burnout and lower open rates.
  • Technical Issues: Emails getting clipped or improper one-click unsubscribe can negatively impact open rates.
  • External Factors: External factors like holidays or seasonal trends influence open rates.
  • Domain Reputation: Check domain reputation with providers to see if deliverability has dropped.

Key considerations

  • Check Domain Reputation: Monitor domain reputation using tools like Google Postmaster Tools and Microsoft SNDS.
  • Implement One-Click Unsubscribe: Ensure proper implementation of one-click unsubscribe, including HTTPS and List-Unsubscribe-Post headers.
  • Analyze Recipient Domain: Check open and click rates by recipient domain to identify issues with specific mailbox providers.
  • Refine Content Strategy: Gather subscriber feedback and adjust content to align with their interests and needs.
  • Segment Your List: Segment your email list based on demographics, interests, and engagement levels.
  • Optimize Email Rendering: Test emails across various devices and email clients to ensure optimal rendering.
  • Subject Lines: Ensure subject lines are engaging and tested for optimal performance.
  • Optimize Sending Frequency: Determine an appropriate email sending frequency to avoid subscriber burnout.
Marketer view

Marketer from Email Geeks asks about the presence of `List-Unsubscribe-Post` and suggests checking server logs for Google's POST requests to the unsubscribe URL, and also to check if there any rate limiting is impacting Google POSTing to those URLs.

October 2024 - Email Geeks
Marketer view

Email marketer from Reddit suggests that increased sending frequency without providing valuable content can lead to subscriber burnout and decreased open rates. Even if emails are inboxing, subscribers may simply be overwhelmed and choose to ignore them.

February 2022 - Reddit
Marketer view

Email marketer from Mailjet Blog explains that decreased open rates despite good inbox placement can stem from list fatigue. Subscribers may be receiving too many emails or the content is no longer relevant, leading to disengagement. Regular list cleaning and segmentation are recommended to target the right audience with the right content.

November 2023 - Mailjet Blog
Marketer view

Email marketer from Neil Patel's Blog explains that lack of segmentation can lead to decreased engagement. Sending the same email to everyone on your list, regardless of their interests or past behavior, can result in irrelevant content and lower open rates, even with good inbox placement.

June 2024 - Neil Patel's Blog
Marketer view

Email marketer from Campaign Monitor Blog explains that Apple's Mail Privacy Protection (MPP) inflates open rates, masking true engagement. A drop after its implementation doesn't necessarily mean a deliverability issue, but rather a more accurate reflection of actual opens. Focus should shift to other metrics like clicks and conversions.

March 2024 - Campaign Monitor Blog
Marketer view

Email marketer from Stack Overflow notes that a sudden shift in subject line performance (becoming less engaging) can cause a drop in open rates. Suggests A/B testing new subject lines.

September 2021 - Stack Overflow
Marketer view

Email marketer from Quora answers that even with good inbox placement, external factors like holidays or seasonal trends influence open rates. Subscriber behaviour may change based on these external influences.

May 2021 - Quora
Marketer view

Email marketer from Email on Acid explains that if an email isn't rendering correctly on certain devices or email clients, subscribers may delete it without opening. Test emails across various platforms to ensure optimal viewing experience and maintain engagement.

October 2021 - Email on Acid
Marketer view

Marketer from Email Geeks mentions Google having issues with the lack of one-click unsubscribe and asks if the one click unsubscribe header is implemented, also if the link is HTTPS and if the additional header under it that defines the unsubscribe as one click post is present.

October 2024 - Email Geeks
Marketer view

Email marketer from Gmass explains that the emails might be getting clipped above your open tracking pixel which results in the email not being tracked as opened.

April 2022 - GMass
Marketer view

Email marketer from Litmus explains that if the content is no longer resonating with subscribers, they will stop opening emails even if they land in the inbox. Analyze subscriber behavior, gather feedback, and adjust content strategy to align with their interests and needs.

September 2024 - Litmus
Marketer view

Marketer from Email Geeks suggests checking open and click rates by recipient domain to identify if a specific mailbox provider is experiencing issues. Single-digit open rates often indicate spam placement and recommends checking Google Postmaster Tools.

July 2021 - Email Geeks

What the experts say
3Expert opinions

Despite emails reaching the inbox, sudden drops in open rates can be attributed to Google's one-click unsubscribe requirements, graymail suppression implemented by mailbox providers (filtering emails out of the primary inbox), or a decline in domain reputation leading to throttling or placement in less prominent tabs. Regular monitoring of domain reputation, correct implementation of one-click unsubscribe, and awareness of graymail suppression are crucial.

Key opinions

  • One-Click Unsubscribe: Google prioritizes correct one-click unsubscribe implementation.
  • Graymail Suppression: Mailbox providers may suppress graymail, filtering emails from primary inboxes due to low engagement.
  • Domain Reputation: Declining domain reputation can cause ISPs to throttle emails or place them in less prominent tabs.

Key considerations

  • Test with AboutMyEmail: Send a test email to aboutmy.email to identify potential issues.
  • Monitor Domain Reputation: Regularly monitor your domain reputation with ISPs and anti-spam organizations.
  • Implement One-Click Unsubscribe: Ensure correct one-click unsubscribe implementation.
  • Engagement Monitoring: Actively monitor and address low engagement to avoid graymail suppression.
Expert view

Expert from Spam Resource explains that even with emails reaching the inbox, a sudden drop in open rates could signify a decline in domain reputation. ISPs might be throttling your emails or placing them in less prominent inbox tabs due to perceived reputation issues. Regularly monitor your domain reputation and ensure compliance with sending best practices.

February 2025 - Spam Resource
Expert view

Expert from Word to the Wise explains that a sudden drop in open rates despite good inbox placement can be caused by mailbox providers implementing graymail suppression. This means that emails are being delivered but filtered out of the primary inbox, effectively hiding them from users. This can be triggered by low engagement and is something senders need to actively monitor and address.

April 2022 - Word to the Wise
Expert view

Expert from Email Geeks suggests that Google prioritizes correct implementation of one-click unsubscribe and advises checking that aspect first. They also suggest sending email to aboutmy.email to identify potential issues and sharing the results for further advice.

November 2022 - Email Geeks

What the documentation says
3Technical articles

Even if emails are bypassing spam filters, a sudden drop in open rates can indicate underlying issues related to sender reputation and technical implementation. Google's documentation highlights that spam complaints aren't recorded for emails landing in spam, while Microsoft emphasizes the importance of maintaining a positive sender reputation. RFC documentation specifies the correct implementation of `List-Unsubscribe-Post`, which is crucial for deliverability. Overall, continuous monitoring of sender reputation, proper technical setup, and adherence to best practices are essential.

Key findings

  • Spam Complaint Blind Spot: Spam complaints are not recorded for emails that land directly in the spam folder.
  • Sender Reputation: Maintaining a positive sender reputation is crucial, even if emails reach the inbox.
  • List-Unsubscribe-Post: Proper implementation of `List-Unsubscribe-Post` is essential for deliverability and user experience.

Key considerations

  • Use Google Postmaster Tools: Utilize Google Postmaster Tools to check deliverability and spam rates.
  • Monitor Microsoft SNDS: Use Microsoft's Smart Network Data Services (SNDS) to monitor sender reputation.
  • Verify List-Unsubscribe-Post: Ensure the URL for `List-Unsubscribe-Post` is controlled by you and that Google's POST requests are handled correctly.
  • Review Sending Practices: Review sending practices, authentication methods, and engagement metrics to address any issues affecting reputation.
Technical article

Documentation from Google explains that if mail lands in spam, it doesn’t record spam complaints. Google Postmaster Tools is a tool to check the deliverability and spam rate of emails sent from your domain.

May 2021 - Google
Technical article

Documentation from RFC explains about implementing `List-Unsubscribe-Post` and ensuring that the URL is a domain that can control. Also checking if logs show Google making POST requests to the URL and if yes, what's the response?

February 2023 - RFC
Technical article

Documentation from Microsoft explains that maintaining a positive sender reputation is crucial. Sudden drops in open rates might indicate a decline in sender reputation, even if emails are still reaching the inbox. Review sending practices, authentication methods, and engagement metrics to identify and address any issues affecting reputation.

July 2021 - Microsoft