What KPIs should I use to monitor email deliverability trends?

Summary

Monitoring email deliverability trends involves a multifaceted approach encompassing technical aspects, engagement metrics, and sender reputation. Key technical KPIs include bounce rates, SMTP error codes, and the implementation of SPF, DKIM, and DMARC. Sender reputation is tracked through spam complaints, blocklist status, and feedback loops, with tools like Google Postmaster Tools and Microsoft SNDS providing valuable insights. Engagement metrics, such as open rates, click-through rates, and conversion rates, offer a view of subscriber interaction, segmented by device and ISP. List hygiene, including managing hard bounces and unengaged subscribers, is critical. Analyzing data over time, rather than relying on one-day numbers, is essential for identifying meaningful trends. Indirect indicators like sudden unsubscribe spikes or low conversion rates can signal deliverability issues. Placement rates, representing emails reaching the inbox versus spam, are a direct measure of success. Actively monitoring and addressing complaints and continuously checking blocklist status are recommended for maintaining a healthy sending reputation. The Apple privacy changes don't impact the validity of trend analysis.

Key findings

  • Sender Reputation: Maintaining a positive sender reputation is paramount, monitored through bounce rates, spam complaints, and blocklist status.
  • Engagement Metrics: Engagement KPIs (open rates, click-through rates, conversion rates) reflect subscriber interaction and campaign effectiveness.
  • Trend Analysis Over Time: Analyzing data over time is crucial to understand meaningful trends, rather than relying on single-day data snapshots.
  • Email Authentication Protocols: Proper implementation of SPF, DKIM, and DMARC is essential for email authentication and improved deliverability.
  • List Hygiene: Managing hard bounces and unengaged subscribers is essential to maintain a clean and responsive email list.
  • Postmaster Tools Monitoring: Leveraging Google Postmaster Tools and Microsoft SNDS gives direct insight into sender reputation.

Key considerations

  • Holistic Approach is Key: Employ a holistic approach that blends technical KPIs, engagement insights, and sender reputation data for a comprehensive view of deliverability.
  • Address Complaints Immediately: Address high complaint rates and bounce reasons promptly to preserve sending reputation and deliverability health.
  • Actively Monitor: Continually monitor deliverability metrics, as a proactive approach helps mitigate potential issues before they escalate.
  • Segementation by ISP: Segment engagement by ISP to gain better insights for B2C senders.
  • Use Feedback Loops: Use Feedback Loops to promptly address any complaints and improve email practices.

What email marketers say
10Marketer opinions

Email deliverability monitoring involves tracking a range of KPIs to ensure emails reach recipients' inboxes and maintain a positive sender reputation. These KPIs span technical aspects like sender reputation (assessed via bounce rates, spam complaints, blocklist status), engagement metrics (open rates, click-through rates, conversion rates), and list hygiene (hard bounces, unengaged subscribers). Postmaster tools and feedback loops are crucial for identifying and resolving deliverability issues. Monitoring placement rates, engagement across devices, and authentication methods (SPF, DKIM, DMARC) also provide insights into deliverability health. Spikes in unsubscribes or low conversion rates can indicate underlying problems. Regularly checking blocklist status and understanding SMTP error codes are essential for proactive issue resolution.

Key opinions

  • Sender Reputation: Monitoring bounce rates, spam complaints, and blocklist status is crucial for maintaining a positive sender reputation.
  • Engagement Metrics: Open rates, click-through rates, and conversion rates offer insights into how subscribers interact with emails.
  • List Hygiene: Tracking hard bounces and unengaged subscribers helps maintain a clean and engaged email list.
  • Placement Rate: Placement rate, the percentage of emails reaching the inbox, is a direct measure of deliverability success.
  • Authentication: Proper implementation and monitoring of SPF, DKIM, and DMARC records are essential for email authentication.
  • Complaint Rates: High complaint rates significantly impact sender reputation and require immediate attention.

Key considerations

  • Holistic Approach: Consider a holistic approach by combining various metrics for a complete picture of deliverability health.
  • Trend Analysis: Monitor trends over time rather than relying on single-day data for more accurate insights.
  • Device-Specific Engagement: Analyze engagement metrics across different devices and email clients to identify potential issues.
  • Proactive Monitoring: Regularly check blocklist status and use postmaster tools to proactively identify and address deliverability issues.
  • Feedback Loops: Implement feedback loops to promptly address complaints and improve email practices.
  • Indirect Indicators: Monitor indirect indicators like conversion rates and unsubscribe spikes as potential signs of deliverability problems.
Marketer view

Email marketer from StackOverflow explains that while unsubscribes are normal, a sudden spike can indicate deliverability problems, such as sending to unengaged or outdated lists.

December 2022 - StackOverflow
Marketer view

Email marketer from HubSpot shares that list hygiene, including tracking hard bounces and unengaged subscribers, is crucial for maintaining deliverability and preventing spam complaints.

December 2021 - HubSpot
Marketer view

Email marketer from Gmass explains that regularly checking your sending IP and domain against various blocklists is essential for identifying and resolving deliverability issues that could prevent emails from reaching inboxes.

November 2024 - Gmass
Marketer view

Email marketer from Email Geeks highlights the importance of trending email metrics, revenue, and other KPIs, as well as the importance of using postmaster tools and sender reputation tools to check deliverability.

December 2023 - Email Geeks
Marketer view

Email marketer from Litmus explains that tracking engagement metrics like open rates and click-through rates across different devices and email clients provides valuable insights into subscriber behavior and campaign performance.

February 2025 - Litmus
Marketer view

Email marketer from Validity shares that placement rate, which measures the percentage of emails that reach the inbox versus the spam folder, is a key indicator of deliverability success.

June 2024 - Validity
Marketer view

Email marketer from Email on Acid explains that monitoring spam complaints and feedback loops is critical for maintaining a positive sender reputation. High complaint rates can lead to deliverability issues and blacklisting.

December 2024 - Email on Acid
Marketer view

Email marketer from ActiveCampaign shares that monitoring complaint rates is critical for maintaining a positive sending reputation. Using feedback loops helps to promptly handle complaints and resolve deliverability issues.

February 2023 - ActiveCampaign
Marketer view

Email marketer from Mailjet explains that sender reputation is vital and should be monitored through bounce rates, spam complaints, and blocklist status. Engagement metrics like open rates, click-through rates, and conversion rates offer insights into subscriber interaction and campaign effectiveness.

February 2022 - Mailjet
Marketer view

Email marketer from Reddit shares that while not direct, conversion rates from email campaigns can indirectly indicate deliverability health. If emails aren't reaching inboxes, conversions will suffer.

November 2024 - Reddit

What the experts say
5Expert opinions

Experts emphasize the importance of tracking email deliverability trends over time using various KPIs. Graphing metrics such as engagement (opens, clicks) and breaking them down by recipient ISP (Gmail, Yahoo, etc.) provides valuable insights. Complaint rates and bounce logs (with reasons) are crucial for understanding deliverability issues and identifying remediation pathways. Monitoring engagement is key, as low engagement can lead to emails being filtered as spam. The Apple privacy changes do not negate the value of trend analysis. Addressing high complaint rates actively is essential for maintaining a healthy sender reputation.

Key opinions

  • Trend Analysis: Graphing deliverability metrics over time is crucial for identifying trends and avoiding reliance on single-day data.
  • Engagement Metrics: Monitoring engagement metrics like opens and clicks is essential for assessing deliverability health and preventing spam filtering.
  • ISP Segmentation: Breaking down metrics by recipient ISP (Gmail, Yahoo, Microsoft) provides valuable insights into deliverability performance.
  • Complaint Rates: Complaint rates are a critical indicator of deliverability issues and significantly impact sender reputation.
  • Bounce Logs: Tracking bounce logs and their reasons helps identify specific deliverability problems and remediation pathways.

Key considerations

  • Apple Privacy Changes: The Apple privacy changes do not invalidate the use of trend analysis for deliverability monitoring.
  • Active Remediation: Actively addressing high complaint rates and bounce reasons is essential for maintaining a healthy sender reputation and improving deliverability.
  • Proactive Monitoring: Continuously monitor deliverability metrics and trends to proactively identify and address potential issues before they impact sending reputation.
Expert view

Expert from Spamresource.com explains the importance of engagement metrics like opens and clicks as indicators of deliverability, noting that sustained low engagement can lead to emails being filtered as spam. They advise monitoring these metrics closely to maintain a healthy sender reputation.

November 2021 - Spamresource.com
Expert view

Expert from Email Geeks shares that the ability to graph metrics over time, broken down by recipient ISP (e.g., Gmail, Yahoo, Microsoft), can be good enough for B2C.

January 2025 - Email Geeks
Expert view

Expert from Email Geeks explains that the changes from Apple do not impact the efficacy of looking at trends.

May 2024 - Email Geeks
Expert view

Expert from Word to the Wise explains that complaint rates are a critical metric for monitoring email deliverability trends, as high complaint rates directly impact sender reputation and can lead to deliverability issues. They recommend actively monitoring and addressing complaints to maintain a healthy sending reputation.

May 2022 - Word to the Wise
Expert view

Expert from Email Geeks explains the importance of graphing everything over time and following trends, as relying on one-day numbers is unreliable. She also advises to keep track of bounce logs and their reasons, as spam filters provide reasons and remediation pathways.

August 2022 - Email Geeks

What the documentation says
5Technical articles

Technical documentation emphasizes the importance of monitoring several KPIs for email deliverability trends. Bounce rates are key for identifying issues with list hygiene and sender reputation. Domain and IP reputation metrics, as provided by Google Postmaster Tools, offer insights into how Gmail views sending practices. Similarly, Microsoft SNDS highlights the significance of monitoring IP reputation and spam trap hits for Outlook.com and Hotmail. SMTP error codes provide detailed information about delivery failures, aiding in diagnosis. Finally, proper implementation and validation of SPF, DKIM, and DMARC are crucial for email authentication and improving deliverability.

Key findings

  • Bounce Rates: High bounce rates indicate problems with email list hygiene or sender reputation.
  • Reputation Metrics: Domain and IP reputation metrics from Google Postmaster Tools are crucial for understanding Gmail's perspective.
  • Spam Trap Hits: Monitoring IP reputation and spam trap hits via Microsoft SNDS helps maintain a positive reputation with Outlook.com and Hotmail.
  • SMTP Error Codes: SMTP error codes provide detailed information for diagnosing delivery failures.
  • Email Authentication: Proper implementation and validation of SPF, DKIM, and DMARC are essential for email authentication.

Key considerations

  • Holistic Technical Monitoring: Employ a comprehensive approach by monitoring all key technical KPIs for a complete view of deliverability.
  • Utilize Postmaster Tools: Leverage tools like Google Postmaster Tools and Microsoft SNDS to gain direct insights into sender reputation.
  • Address Bounce Reasons: Analyze bounce logs to understand the specific reasons for delivery failures and implement corrective measures.
  • Maintain Authentication: Ensure proper configuration and validation of SPF, DKIM, and DMARC records to prevent authentication-related deliverability issues.
Technical article

Documentation from Google Postmaster Tools explains that domain and IP reputation metrics are crucial for understanding how Gmail views your sending practices. Monitoring these metrics can help identify and resolve deliverability issues.

September 2023 - Google
Technical article

Documentation from MessageBird, formerly SparkPost, explains that tracking the implementation and validation of SPF, DKIM, and DMARC records is essential for authenticating emails and improving deliverability.

December 2021 - MessageBird
Technical article

Documentation from Microsoft SNDS explains that monitoring IP reputation and spam trap hits can help identify deliverability issues and maintain a positive sending reputation with Outlook.com and Hotmail.

January 2023 - Microsoft
Technical article

Documentation from SendGrid explains that tracking bounce rates is essential for identifying deliverability issues. High bounce rates can indicate problems with email list hygiene or sender reputation.

October 2021 - SendGrid
Technical article

Documentation from IETF explains that SMTP error codes provide detailed information about delivery failures. Analyzing these codes can help diagnose deliverability issues.

January 2025 - IETF