Summary
Email deliverability issues for high-volume clients, even without deliberate configuration changes, can stem from a multitude of internal and external factors. Key influences include fluctuations in sender reputation due to spam complaints, blacklisting, and sudden volume changes; the relevance and engagement of email content affecting how ISPs perceive the sender; changes in recipient behavior like increased spam flagging; problems related to shared IP addresses where other senders' actions impact deliverability; failures to manage feedback loops, list hygiene, and emerging threats such as phishing; overly strict DMARC policies; mailbox provider algorithm changes; authentication issues from DNS changes; exceeding sending limits, and the need for ongoing monitoring of deliverability, IP reputation, and engagement metrics. Even a simple mistake such as accidently not emailing to a specific inbox provider can have major impacts.
Key findings
- Sender Reputation Fluctuations: Sudden drops in sender reputation due to spam complaints or blacklisting affect deliverability.
- Content Relevance: Irrelevant content leads to decreased engagement, impacting ISP perception.
- Recipient Behavior Changes: Increased spam flagging and decreased open rates negatively impact deliverability.
- Shared IP Problems: Other senders' actions on shared IPs influence deliverability.
- Feedback Loop Neglect: Improper handling of spam reports causes deliverability issues.
- List Hygiene Decline: Poor list hygiene increases bounce rates and spam complaints.
- Emerging Threat Neglect: Lack of awareness of phishing harms sender reputation.
- Strict DMARC Policies: Overly strict DMARC blocks legitimate emails.
- Algorithm Changes: Mailbox provider algorithm changes require constant monitoring.
- Authentication Issues: DNS changes impact email authentication.
- Volume Exceeding Limitations: Exceeding volume with no warm-up period causes issues.
Key considerations
- Monitor Sender Reputation: Regularly check sender reputation and promptly address issues.
- Ensure Content Relevance: Keep email content engaging and targeted.
- Monitor IP and Sending Practices: Monitor shared IPs and avoid volume spikes and be careful not to pause sending to segments
- Manage Feedback Loops: Address spam reports effectively.
- Maintain List Hygiene: Regularly clean email lists.
- Address Emerging Threats: Implement phishing detection.
- Check DMARC Configuration: Adjust DMARC for balance.
- Monitor Algorithm Changes: Stay updated with provider changes.
- Verify Authentication: Confirm SPF, DKIM, DNS.
- Review Verification Status: Confirm volume levels are correct.
What email marketers say
10 marketer opinions
Email deliverability issues with high-volume clients, despite no configuration changes, can stem from various external and internal factors. These include fluctuations in sender reputation due to spam complaints or blacklisting, content irrelevance leading to low engagement, changes in recipient behavior such as increased spam flagging, issues related to shared IP addresses, unforeseen blacklisting or bot activity, poor feedback loop management, overly strict DMARC policies, and mailbox provider algorithm changes. Monitoring deliverability is crucial to identify and address these issues proactively.
Key opinions
- Sender Reputation: A sudden drop in sender reputation, often due to spam complaints or blacklisting, can cause deliverability issues even without configuration changes.
- Content Relevance: Irrelevant content leads to lower engagement, causing ISPs to flag emails as less important and affecting deliverability.
- Recipient Behavior: Changes in how recipients interact with emails, such as increased spam flagging or decreased open rates, can negatively impact deliverability.
- Shared IP Issues: High-volume clients on shared IPs can be affected by the actions of other senders, leading to deliverability problems.
- Blacklisting: Unforeseen spam complaints or bot activity can lead to blacklisting, severely affecting email delivery.
- Feedback Loops: Not properly managing feedback loops (spam reports) can result in deliverability issues.
- DMARC Policies: Overly strict DMARC policies can cause deliverability problems if authentication fails intermittently.
- Algorithm Changes: Mailbox provider algorithm updates can impact deliverability, necessitating continuous monitoring.
Key considerations
- Monitor Reputation: Regularly monitor sender reputation to identify and address any sudden drops or blacklisting issues.
- Content Quality: Ensure email content remains relevant and engaging to maintain high open rates and low spam complaints.
- IP Management: If using a shared IP, be aware of the potential impact from other senders and consider dedicated IPs for high-volume clients.
- Feedback Loop Handling: Implement and actively manage feedback loops to promptly address and resolve spam complaints.
- DMARC Configuration: Review and adjust DMARC policies to balance security with deliverability, ensuring legitimate emails are not blocked.
- Deliverability Monitoring: Continuously monitor deliverability metrics to detect and respond to algorithm changes and other external factors affecting email delivery.
Marketer view
Email marketer from Neil Patel's Blog explains that a sudden drop in sender reputation can cause email issues even without setting changes. This could be due to spam complaints or blacklisting.
17 Feb 2022 - Neil Patel's Blog
Marketer view
Email marketer from Sendinblue explains that changes in recipient behavior, such as increased spam flagging or decreased open rates, can negatively impact deliverability even if settings remain unchanged.
28 Sep 2024 - Sendinblue
What the experts say
3 expert opinions
Email deliverability issues for high-volume clients, even without changes in settings, can arise from several factors. These include a decline in list hygiene, leading to increased bounce rates and spam complaints; sudden reputation declines due to unexpected blacklisting events or unusual volume changes; and a failure to address emerging threats like phishing attacks that leverage the client's domain.
Key opinions
- List Hygiene: A decline in list hygiene (increase in stale/invalid addresses) results in increased bounce rates and spam complaints, negatively impacting deliverability.
- Reputation Declines: Sudden reputation declines can stem from unexpected blacklisting events or sudden volume changes that are misinterpreted as spam.
- Emerging Threats: Lack of awareness and action against emerging threats like phishing attacks using the domain harms sender reputation and deliverability.
Key considerations
- Maintain List Hygiene: Regularly clean and validate email lists to remove stale or invalid addresses, reducing bounce rates and spam complaints.
- Monitor Reputation: Keep a close watch on sender reputation to detect and address blacklisting events or unusual volume changes promptly.
- Address Emerging Threats: Implement measures to detect and prevent phishing attacks and other emerging threats that could damage sender reputation.
Expert view
Expert from Word to the Wise, Dennis Dayman, explains that a lack of awareness and action on emerging threats like phishing attacks leveraging your domain can harm your sender reputation and thus email deliverability, despite no internal configuration changes.
5 Feb 2024 - Word to the Wise
Expert view
Expert from Word to the Wise, Laura Atkins, explains that even without setting changes, a decline in list hygiene (increase in stale or invalid addresses) can lead to increased bounce rates and spam complaints, negatively affecting deliverability.
10 Dec 2021 - Word to the Wise
What the documentation says
5 technical articles
Email deliverability issues with high-volume clients, even when settings remain unchanged, can be caused by several factors highlighted in documentation. These include continuous updates to spam filters by providers like Gmail that may inadvertently affect legitimate senders, the critical importance of maintaining a good IP reputation (particularly on shared IPs), authentication failures due to DNS record changes or misconfigurations even with proper SPF/DKIM setup, blacklisting resulting from sudden increases in spam complaints, and exceeding sending limits or sudden volume spikes, even if within configured parameters.
Key findings
- Spam Filter Updates: Gmail's continuously updated spam filters can inadvertently affect legitimate senders, causing deliverability problems.
- IP Reputation: Maintaining a good IP reputation is crucial; a sudden drop (e.g., from shared IP spam) can lead to deliverability issues.
- Authentication Failures: Even with correct initial SPF/DKIM, DNS record changes or other misconfigurations can cause authentication failures.
- Spam Complaints & Blacklisting: Sudden increases in spam complaints can lead to blacklisting, regardless of other settings.
- Sending Limits & Volume Spikes: Exceeding sending limits or experiencing sudden volume spikes (even within configured limits) can trigger throttling and reduce deliverability.
Key considerations
- Monitor Spam Filters: Stay informed about changes to spam filtering algorithms and adapt sending practices accordingly.
- Maintain IP Reputation: Actively monitor and maintain IP reputation, especially when using shared IPs, to prevent deliverability problems.
- Ensure Proper Authentication: Regularly verify DNS records and SPF/DKIM configurations to ensure proper email authentication.
- Manage Spam Complaints: Implement measures to reduce spam complaints, such as list hygiene and targeted content, and monitor feedback loops.
- Control Sending Volume: Gradually increase sending volume and avoid sudden spikes, particularly when starting with a new IP or domain.
Technical article
Documentation from Google Workspace Admin Help explains that Gmail's spam filters are constantly updated, and these updates can sometimes inadvertently affect legitimate senders, causing deliverability issues even without any changes on the sender's side.
25 Jun 2024 - Google Workspace Admin Help
Technical article
Documentation from AWS explains that exceeding sending limits (even if within allowed configurations) can trigger throttling and reduced deliverability. Sudden volume spikes without warming up can lead to issues.
23 Sep 2022 - AWS Documentation
