Summary
A sudden drop in email open rates can be caused by a multitude of interconnected issues. Core problems include deliverability issues arising from poor sender reputation, DBL listings, non-compliance with Yahoo/Google requirements (especially regarding DKIM, SPF, and DMARC), and problematic ESP practices. Changes to email client filtering, increased inbox competition, and emerging privacy measures also influence open rates. To combat this, experts advise auditing and improving sender reputation through Google Postmaster Tools, verifying correct SPF and DKIM implementation, segmenting and personalizing email content to improve audience engagement, re-engaging inactive subscribers, and potentially switching to a more competent ESP. Furthermore, review your email frequency, ensure one-click unsubscribe links are present, implement double opt-in, and monitor where your emails are landing.
Key findings
- Technical Compliance Issues: Failure to comply with Yahoo and Google's requirements regarding SPF, DKIM, DMARC, and one-click unsubscribe directly impacts deliverability.
- ESP Competence: An ESP not supporting required standards (e.g., Yahoo/Google compliance) or having deliverability problems (DBL listings) significantly hinders email performance.
- Deliverability Factors: Deliverability is influenced by sender reputation, IP blacklisting, inbox placement (spam/promotions tabs), and email client filtering.
- Audience Engagement: Low engagement, list fatigue, and irrelevant content contribute to decreased open rates; segmentation and personalization are crucial.
- Privacy Impacts: New privacy policies by companies like Apple impact tracking accuracy, requiring a broader approach to success measurement.
Key considerations
- ESP Evaluation: Evaluate your current ESP's capabilities and compliance; switch if necessary to ensure a baseline level of deliverability.
- Technical Audit: Conduct a thorough technical audit of SPF, DKIM, and DMARC configurations to ensure correct setup and authentication.
- Reputation Management: Actively monitor and manage sender reputation using tools like Google Postmaster Tools; address any issues promptly.
- Engagement Strategies: Implement list cleaning, re-engagement campaigns, segmentation, and personalization to improve audience engagement and relevance.
- Holistic Measurement: Recognize the limitations of open rate metrics and consider other KPIs (e.g., clicks, conversions) to measure campaign success effectively.
- Consent and Preference: Prioritize obtaining explicit consent (double opt-in) and offering easy unsubscribe options to ensure you're sending wanted emails.
What email marketers say
10 marketer opinions
A sudden drop in email open rates can stem from various factors. These include changes in email client algorithms, increased competition, list fatigue, deliverability issues, poor subject lines, outdated lists, or a lack of audience resonance. The trend towards increased privacy may also impact the accuracy of open rates. Recommendations include re-engaging inactive subscribers, improving relevance through segmentation and personalization, optimizing send times, ensuring proper authentication (SPF, DKIM, DMARC), cleaning email lists, testing subject lines, monitoring sender reputation, spacing out email sends, tracking device usage, implementing one-click unsubscribe, and using double opt-in to ensure wanted emails are sent.
Key opinions
- Deliverability Issues: Poor sender reputation, being blacklisted, or failing authentication checks (SPF, DKIM, DMARC) can directly impact deliverability and open rates.
- Audience Engagement: Lack of relevance, list fatigue, or unengaging content can lead to lower open rates. Segmentation and personalization are crucial for maintaining audience interest.
- External Factors: Changes in email client algorithms, increased competition in the inbox, and privacy-related updates (like Apple's Mail Privacy Protection) can all affect open rate accuracy and overall performance.
- Technical Compliance: Google and Yahoo require one-click unsubscribe. Non-compliance effects sender reputation.
- List Hygiene: Sending too frequently or to non-engaged recipients/spam traps hurts your deliverability.
Key considerations
- Authentication: Verify that SPF, DKIM, and DMARC are correctly configured to ensure emails are authenticated and not marked as spam.
- List Management: Implement strategies for cleaning email lists, re-engaging inactive subscribers, and using double opt-in to maintain a healthy and engaged audience.
- Content Optimization: Improve email relevance by segmenting your audience, personalizing content, and testing different subject lines to increase engagement.
- Monitoring & Analysis: Track device usage, sender reputation, and deliverability metrics to identify potential issues and optimize email campaigns accordingly.
- Unsubscribe Options: Ensure easy and accessible unsubscribe options, especially one-click unsubscribe, to comply with regulations and maintain a positive sender reputation.
Marketer view
Email marketer from Sendinblue Blog shares that decreased open rates often stem from deliverability issues, poor subject lines, or sending to outdated lists. They recommend cleaning your email list, testing subject lines, and ensuring proper authentication (SPF, DKIM, DMARC).
15 May 2024 - Sendinblue Blog
Marketer view
Email marketer from Mailjet Blog explains that a sudden drop in email open rates can be due to various factors, including changes in email client algorithms, increased competition in the inbox, and list fatigue. They suggest strategies like re-engaging inactive subscribers, improving email relevance, and optimizing send times.
14 Apr 2025 - Mailjet Blog
What the experts say
6 expert opinions
A sudden drop in email open rates can be attributed to several key issues according to experts. These include the impact of DBL listings affecting prefetching at Gmail, non-compliance with Yahoo/Google requirements affecting prefetching, changes in email client filtering and increased inbox competition, and inbox placement issues. Experts recommend addressing major issues first, potentially switching email platforms if necessary, checking inbox placement (spam/promotions), reviewing sender reputation, authentication protocols, and engaging subscribers to confirm audience reach.
Key opinions
- DBL Listing Impact: DBL listings (Domain Blocklist) can negatively affect email prefetching at Gmail, leading to lower open rates.
- Yahoo/Google Compliance: Failure to comply with Yahoo and Google's email requirements can impact prefetching and overall deliverability.
- Deliverability Issues: Open rate drops may indicate broader deliverability problems, such as emails landing in the spam folder or promotions tab.
- Platform Limitations: Underlying issues from ESPs such as lack of compliancy, DBL listings and no available fixes suggest it's time to switch platforms.
- Sender reputation and filtering: Changes in email client filtering and increase competition in the inbox, are other contributing factors to open rate decline.
Key considerations
- Address Major Issues First: Prioritize addressing fundamental problems like DBL listings and compliance with email provider requirements before other optimizations.
- Evaluate ESP: Consider switching email platforms if the current ESP cannot resolve key deliverability issues or meet industry standards.
- Monitor Inbox Placement: Regularly check where emails are landing (inbox, spam, promotions) to identify and address deliverability problems.
- Review Reputation and Authentication: Assess sender reputation, authentication protocols (SPF, DKIM, DMARC), and engagement metrics to identify areas for improvement.
- Subscriber Engagement: Confirm that emails are reaching the intended audience and engage subscribers to improve sender reputation and reduce the likelihood of being filtered as spam.
Expert view
Expert from Email Geeks suggests that with multiple major issues against them, other advice is irrelevant until those issues are addressed.
31 May 2024 - Email Geeks
Expert view
Expert from Word to the Wise responds that a sudden drop in open rates may indicate a deliverability issue, potentially caused by changes in inbox placement. She recommends checking if you are landing in the spam folder or promotions tab and troubleshooting from there.
23 Oct 2024 - Word to the Wise
What the documentation says
4 technical articles
According to documentation, a sudden drop in email open rates can be linked to issues with domain reputation, SPF record misconfigurations, DKIM signature failures, and non-compliance with email provider requirements. Google Postmaster Tools can help monitor sender reputation. It's crucial to ensure the sending server's IP address is in the SPF record, all emails are signed with DKIM, and you meet Yahoo's requirements for avoiding spam classification, including correct DKIM, SPF, and DMARC configuration, a good sender reputation, and sending wanted emails.
Key findings
- Sender Reputation: A drop in open rates may indicate a decline in sender reputation.
- SPF Configuration: SPF records failing due to incorrect sending server IP addresses can impact deliverability.
- DKIM Signing: Failure to properly sign emails with DKIM can lead to deliverability issues.
- Compliance: Not following email provider rules causes email to be marked as spam
Key considerations
- Monitor Sender Reputation: Use tools like Google Postmaster Tools to track and maintain a good sender reputation.
- Verify SPF Records: Ensure the SPF record includes the correct sending server IP address to prevent authentication failures.
- Implement DKIM Signing: Sign all outgoing emails with DKIM to ensure authenticity and improve deliverability.
- Meet Provider Requirements: Follow all the specific requirements for Google/Yahoo to prevent emails being flagged as spam.
Technical article
Documentation from DKIM specifies to ensure all emails are signed with DKIM. If this is broken, it can have drastic results on the deliverability of emails as the signature cannot be verified.
13 Jul 2022 - RFC 4871
Technical article
Documentation from Google explains that using Google Postmaster Tools can provide insights into your domain's reputation and deliverability. A drop in open rates may correlate with a decrease in sender reputation, which can be monitored through these tools.
31 Dec 2021 - Google
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