Summary
A sudden drop in email open rates is a multifaceted issue arising from technical configurations, sender reputation, content relevance, and list management practices. Technical aspects involve issues like IP blacklisting, potentially stemming from Sendinblue's shared IP pools, improper DMARC implementation, and ISP-specific filtering. Sender reputation, crucial for deliverability according to Google, Microsoft, and industry experts, is influenced by authentication (SPF, DKIM, DMARC), complaint rates, spam trap hits, and sending volume. Content factors include generic subject lines, spam trigger words, and inconsistent rendering across email clients. List management involves segmenting for relevance, removing inactive subscribers, managing sending frequency to avoid fatigue, and ensuring opt-in consent and value delivery. Re-engagement campaigns and A/B testing are commonly recommended to improve engagement and identify effective strategies.
Key findings
- Technical Configuration Matters: Improper email authentication (SPF, DKIM, DMARC) and IP blacklisting significantly hurt deliverability.
- Sender Reputation is Paramount: ISPs like Gmail and Microsoft heavily rely on sender reputation metrics (complaints, spam traps, engagement) for filtering.
- Content Relevance Drives Engagement: Generic or spammy content leads to filtering or disengagement, lowering open rates.
- List Segmentation is Critical: Sending irrelevant content to a broad audience decreases engagement and can increase complaints.
- List Hygiene Improves Deliverability: Removing inactive subscribers enhances sender reputation and overall engagement rates.
- Testing is Essential: Testing deliverability across different ISP's shows the effectiveness of the deliverability and provide opportunities for areas to improve.
Key considerations
- Audit Technical Setup: Verify SPF, DKIM, and DMARC records. Investigate if the sending IP is blacklisted. Use Postmaster Tools.
- Monitor Sender Reputation: Track complaint rates, spam trap hits, and engagement metrics to identify reputation problems.
- Optimize Email Content: Craft personalized, intriguing subject lines. Avoid spam trigger words. Test rendering across email clients.
- Segment and Personalize Lists: Segment based on demographics, behavior, and purchase history. Tailor content to specific segments.
- Implement List Hygiene Practices: Remove inactive subscribers and implement a re-engagement campaign for potentially lost subscribers.
- Ensure Opt-In and Provide Value: Confirm subscribers opted in and consistently deliver valuable content aligned with their interests.
- Manage Sending Frequency: Avoid overwhelming subscribers with too many emails, potentially leading to fatigue and unsubscriptions.
- Review Recent Changes: Review IP's, domains, from addresses and content to see if any changes have had a negative impact. Change these back if appropriate.
What email marketers say
15 marketer opinions
A sudden drop in email open rates can stem from various interconnected issues. These range from technical problems like IP blacklisting or misconfigured DMARC records, especially with providers like Sendinblue, to broader challenges such as changing email client algorithms, increased inbox competition, and poor sender reputation with ISPs. Content-related factors also play a crucial role, including irrelevant or poorly crafted subject lines and preview text, triggering spam filters with certain words, and inconsistent email rendering across devices. Finally, list management practices significantly impact open rates. Sending too frequently, failing to segment lists for relevant content, and neglecting list hygiene (removing inactive subscribers) all contribute to decreased engagement. Re-engagement campaigns and A/B testing are recommended as ways to improve list health and identify optimal messaging strategies.
Key opinions
- Technical Issues: Blacklisted IPs and incorrect DMARC setups can severely impact deliverability.
- Algorithm Changes: Email client algorithms are constantly evolving, requiring marketers to adapt their strategies.
- Sender Reputation: ISPs consider sender reputation when determining whether to deliver emails to the inbox.
- Content Relevance: Irrelevant or poorly crafted email content leads to decreased engagement.
- List Hygiene: Inactive subscribers negatively impact sender reputation and open rates.
Key considerations
- Technical Audit: Check IP reputation, DMARC configuration, and authentication settings.
- Content Optimization: Improve subject lines and preview text, avoid spam trigger words, and ensure consistent rendering across devices.
- Segmentation & Personalization: Segment lists based on demographics, behavior, and purchase history and create more personalized content.
- Frequency & Timing: Optimize send frequency and timing to avoid subscriber fatigue.
- List Management: Regularly clean your email list to remove inactive subscribers and implement a re-engagement campaign.
- A/B Testing: Use A/B testing to identify subject lines, send times, and content that resonate best with subscribers.
- Engagement Analysis: Monitor unsubscribe rates, engagement rates to better target subscribers and assess list health.
Marketer view
Email marketer from Email Geeks (from Sendinblue) clarifies that advising DMARC implementation as a deliverability fix is incorrect and expresses a desire to remove the problematic DMARC record recommendation.
16 Apr 2023 - Email Geeks
Marketer view
Email marketer from Email Geeks asks about bounce rates and other signals, suggesting checking Postmaster tools.
27 May 2022 - Email Geeks
What the experts say
6 expert opinions
A sudden drop in email open rates can be attributed to a combination of factors related to ISP filtering, sender reputation, and changes in email sending practices. Identifying whether the drop is isolated to a specific ISP can indicate filtering issues, suggesting the need to test delivery to different webmail providers. While IP problems might require ESP intervention, bulk foldering is typically unrelated. Understanding the different types of ISPs and their filtering methods is crucial, as engagement metrics vary across providers. Sudden drops in engagement can also be triggered by alterations to the sending IP, domain, 'From' address, or content. It's essential to monitor sender reputation closely. Finally, maintaining list hygiene, ensuring subscribers have opted in, and delivering on promised value are critical for long-term deliverability.
Key opinions
- ISP-Specific Issues: Open rate drops may be isolated to a specific ISP, indicating filtering problems.
- Sender Reputation: Sudden changes in sending IP, domain, or content can negatively affect sender reputation and trigger filtering.
- ISP Diversity: Different ISPs have different filtering methods, with engagement metrics varying across providers.
- List Hygiene Importance: Maintaining a clean and engaged list is critical for deliverability.
- Blocklisting: Blocklisting is only one factor that can influence deliverability.
Key considerations
- ISP Testing: Create new email addresses at different webmail domains to test delivery and identify ISP-specific issues.
- Sender Reputation Monitoring: Closely monitor sender reputation to identify potential problems.
- List Opt-In Verification: Ensure all subscribers have explicitly opted in to receive emails.
- Value Proposition Delivery: Provide valuable content that aligns with subscribers' expectations.
- Sender Changes Review: Review recent sender changes to determine if there were any changes to IP, domain, 'From' address or content and if so, change it back.
Expert view
Expert from Word to the Wise, Laura Atkins, explains that sudden drops in engagement can be linked to a change of IP, domain, From: address, content or a combination. It is crucial to watch sender reputation closely and that a good volume of mail is needed to establish reputation.
22 Dec 2022 - Word to the Wise
Expert view
Expert from Email Geeks details different types of ISPs (Internet Service Providers) and their filtering methods, including free webmail providers (Gmail, Microsoft, Verizon), European providers, cable providers, and businesses using GSuite/O365. She notes that engagement matters differently based on the ISP type.
4 Jun 2022 - Email Geeks
What the documentation says
3 technical articles
A sudden drop in email open rates is often linked to sender reputation, which is heavily influenced by factors like email authentication, user engagement, sending volume, complaint rates, and spam trap hits. Google, Microsoft, and email standards bodies emphasize the importance of a positive sender reputation for ensuring email deliverability. Implementing SPF, DKIM, and DMARC helps verify sender identity, improving the likelihood of emails reaching the inbox. Failure to maintain a good reputation results in emails being filtered as spam, leading to lower open rates.
Key findings
- Sender Reputation Matters: Gmail and Microsoft prioritize sender reputation when filtering emails.
- Email Authentication is Key: SPF, DKIM, and DMARC are essential for verifying sender identity and improving deliverability.
- Engagement Impacts Delivery: User engagement plays a role in whether emails are delivered to the inbox.
- Sending Practices Influence Reputation: Sending volume, complaint rates, and spam trap hits significantly impact sender reputation.
Key considerations
- Implement Authentication Protocols: Ensure SPF, DKIM, and DMARC are properly configured to authenticate emails.
- Monitor Sender Reputation: Use tools like Google Postmaster Tools to monitor sender reputation metrics.
- Manage Sending Volume: Gradually increase sending volume to avoid triggering spam filters.
- Reduce Complaint Rates: Focus on providing valuable content and segmenting lists to minimize complaints.
- Avoid Spam Traps: Practice proper list hygiene to avoid sending emails to spam traps.
- Encourage User Engagement: Encourage recipients to mark emails as 'not spam' if they are misclassified.
Technical article
Documentation from Microsoft explains that maintaining a good sender reputation is crucial for email deliverability. Factors such as sending volume, complaint rates, and spam trap hits impact sender reputation and can affect open rates.
23 Dec 2022 - Microsoft
Technical article
Documentation from RFC Editor answers that implementing email authentication protocols like SPF, DKIM, and DMARC helps verify the sender's identity and improves email deliverability, which in turn can increase open rates by ensuring emails reach the inbox.
28 Jan 2025 - RFC Editor
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