Why has my sender score dropped and what can I do about it?

Summary

A drop in Sender Score can stem from several interconnected factors, often reflecting underlying deliverability issues. Poor list hygiene, characterized by high bounce rates, spam complaints, sending to spam traps, or acquiring lists from compromised or low-quality sources, significantly impacts Sender Score. Being blacklisted and experiencing sudden spikes in sending volume are also major contributors. Technical aspects like inadequate email authentication (SPF, DKIM, DMARC) and inconsistent sending patterns further erode sender reputation. Engagement metrics, particularly low open rates, serve as indicators of deliverability problems. Shared IP addresses, where the actions of other senders influence your score, add another layer of complexity. Addressing a low Sender Score involves improving list hygiene, warming up new IPs, authenticating emails, ensuring consistent sending practices, delivering valuable content, actively engaging subscribers, monitoring sender reputation using tools like Google Postmaster Tools, investigating recent campaigns for deliverability issues, and optimizing sending infrastructure. Focusing on actual deliverability problems and doing root cause analysis is also considered a good practice, instead of solely focusing on the sender score metric as an absolute value.

Key findings

  • List Hygiene: Poor list hygiene, marked by high bounce rates and spam complaints, directly impacts Sender Score.
  • Authentication: Lack of proper email authentication (SPF, DKIM, DMARC) leads to deliverability issues.
  • Engagement: Low engagement, like poor open rates, reflects negatively on sender reputation.
  • IP Reputation: Blacklisting and blocklisting directly lead to lower sender scores.
  • Sending Volume: Sudden changes in email sending volume will reduce your score.
  • Content Quality: Sending spam content negatively impacts sender reputation and causes plummeting open rates.
  • Shared IP Influence: On shared IPs, other users can affect scores, with above 70 a reasonable target.
  • Algorithm Data: Sender Score calculations include Sender Rejected (blocks/bounces) data points.

Key considerations

  • Monitor Reputation: Routinely use tools to monitor sender reputation and address deliverability challenges.
  • Clean and Segment Lists: Keep lists clean by removing inactive subscribers and segmenting based on engagement.
  • Improve Engagement: Create engaging, valuable content to foster positive subscriber interactions.
  • Optimize Infrastructure: Ensure email infrastructure is properly configured and optimized for deliverability.
  • Authentication: Validate that SPF, DKIM and DMARC records are in place
  • Deliverability Audit: If scores are low, do a deliverability audit.
  • Root Cause Analysis: Identify deliverability issues using root cause analysis.

What email marketers say
15Marketer opinions

A drop in Sender Score can be attributed to several factors, including poor list hygiene (high bounce rates, spam complaints), sudden increases in sending volume, sending spam, being blacklisted, and issues with email authentication. Maintaining a good Sender Score involves email authentication (SPF, DKIM, DMARC), consistent sending practices, providing valuable content, actively engaging subscribers, warming up new IPs, and regularly monitoring sender reputation through tools like Google Postmaster Tools and Sender Score itself. Some suggest not focusing solely on sender score as a metric but focus on whether there are underlying deliverability problems.

Key opinions

  • Factors Affecting Score: Several factors impact Sender Score, including spam complaints, bounces, blacklisting, and sudden changes in sending volume.
  • List Hygiene: Maintaining a clean email list by removing inactive subscribers and managing bounces is crucial for a good Sender Score.
  • Authentication: Implementing email authentication protocols (SPF, DKIM, DMARC) is essential for establishing trust and improving Sender Score.
  • Engagement: Actively engaging subscribers and providing valuable content helps improve sender reputation and Sender Score.
  • Shared IP: When on a shared IP, a score above 70 is reasonable.
  • Sender Rejected: Sender Rejected (blocks / bounces) is one of the data points that go into the Sender Score algorithm.

Key considerations

  • Monitor Deliverability: Regularly monitor your sending reputation using tools like Sender Score and Google Postmaster Tools to identify and address potential issues early on.
  • Investigate Causes: If your Sender Score drops, investigate recent email campaigns for issues like high bounce rates or spam complaints.
  • Optimize Practices: Optimize your sending practices by segmenting lists, improving email content, and warming up new IPs to improve deliverability and Sender Score.
  • Focus on Deliverability: Consider focusing on deliverability as the overall metric and not solely rely on the sender score as an absolute value
Marketer view

Email marketer from Email Geeks advises checking for a sudden increase in subscriptions from compromised forms or poor-quality list sources, which could be causing the sender score to drop.

June 2023 - Email Geeks
Marketer view

Email marketer from SendPulse says that a drop in Sender Score can be caused by sending spam, high bounce rates, low engagement, being blacklisted, or having a sudden spike in sending volume. To fix this, warm up your IP, improve list hygiene, and send relevant content.

August 2024 - SendPulse
Marketer view

Email marketer from Email Geeks suggests focusing on actual deliverability problems rather than solely relying on Sender Score.

May 2024 - Email Geeks
Marketer view

Email marketer from Email Marketing Forum suggests investigating recent email campaigns for issues like high bounce rates or spam complaints. They suggest segmenting lists to reduce bounces and improving email content to decrease spam complaints.

November 2024 - Email Marketing Forum
Marketer view

Email marketer from Gmass shares that maintaining a good sender reputation includes consistently sending valuable content, avoiding spammy practices, and actively engaging with your subscribers to encourage positive interactions.

March 2021 - Gmass
Marketer view

Email marketer from Reddit explains that focusing on email list hygiene, warming up new IPs, and consistent email sending are important. Monitor sender reputation using tools like Google Postmaster Tools.

October 2021 - Reddit
Marketer view

Email marketer from ActiveCampaign that in addition to authentication (SPF, DKIM and DMARC), to also segment lists to send appropriate content to the correct people, monitor deliverability and keep your lists clean.

January 2022 - ActiveCampaign
Marketer view

Email marketer from Email Geeks says >70 is a reasonable score when using a shared IP as you don't own the total output or input.

June 2021 - Email Geeks
Marketer view

Email marketer from Email Geeks suggests that a low sender score combined with some blacklists might indicate being on a less optimal IP address block. They suggest a deliverability audit and optimizing sending practices to potentially improve the IP address block.

December 2023 - Email Geeks
Marketer view

Email marketer from GlockApps explains that key factors impacting deliverability and thus sender score include email authentication, list quality, engagement metrics, and sender reputation. Regularly monitor and optimize these factors to improve deliverability.

October 2023 - GlockApps
Marketer view

Email marketer from MailMonitor advises that to improve your sender score, ensure your sending infrastructure is properly configured, authenticate your email with SPF, DKIM, and DMARC, and follow best practices for list management and email content.

October 2023 - MailMonitor
Marketer view

Email marketer from Email Geeks explains that Sender Rejected (blocks / bounces) are one of the data points that go into the Sender Score algorithm and that a spike in bounces on that IP address can cause the SS to drop.

August 2021 - Email Geeks
Marketer view

Email marketer from Mailjet shares that to improve Sender Score, you should authenticate your emails (SPF, DKIM, DMARC), maintain a clean email list by removing inactive subscribers, and monitor your sending reputation using tools like Sender Score.

September 2022 - Mailjet
Marketer view

Email marketer from Litmus answers that sender reputation is like your credit score for email. The higher your score, the more likely mailbox providers are to deliver your messages to the inbox.

June 2021 - Litmus
Marketer view

Email marketer from Email Geeks says that SS gives you a decent idea of where you stand on the inbox food chain. Not absolute but very useful feedback.

September 2022 - Email Geeks

What the experts say
5Expert opinions

A drop in sender score can be linked to IP address blocklistings, inconsistencies in sending patterns, authentication issues, poor list hygiene, low engagement, high complaint rates, or problems with your infrastructure setup. It can also be signaled by emails landing in spam folders, plummeting open rates, or blacklisting. Shared IPs, like those used by Klaviyo, can affect the score, but recovery is possible. While Sender Score can be useful for root cause analysis, especially for dedicated IPs, drastic changes in any of the factors can impact the score negatively.

Key opinions

  • IP Blocklisting: IP address blocklistings can be a direct cause of a reduced sender score.
  • Inconsistent Sending: Inconsistencies in sending patterns, such as volume and frequency, can negatively impact sender reputation.
  • Authentication Issues: Problems with email authentication can lower sender scores.
  • List Hygiene and Engagement: Poor list hygiene (high bounce rates, spam complaints) and low engagement contribute to reduced sender reputation.
  • Infrastructure Setup: Improperly configured email infrastructure can damage sender score.
  • Shared IPs: Using shared IPs can impact sender score based on the behavior of other users on the same IP.
  • Spam Indication: Emails landing in spam folders or plummeting open rates indicate potential issues affecting sender reputation.

Key considerations

  • Investigate Blocklists: Check if your IP address is on any blocklists and take steps to be removed if necessary.
  • Maintain Consistency: Establish and maintain consistent sending patterns to build a positive sender reputation.
  • Ensure Authentication: Verify that SPF, DKIM, and DMARC records are correctly configured to authenticate your emails.
  • Improve List Hygiene: Regularly clean your email list by removing inactive subscribers and addressing bounce issues.
  • Monitor Engagement: Monitor engagement metrics (open rates, click-through rates) and address any declines promptly.
  • Review Infrastructure: Ensure your email infrastructure is properly configured and optimized for deliverability.
  • Root Cause Analysis: If sender score drops, use tools to do a root cause analysis.
Expert view

Expert from Word to the Wise explains that a number of factors contribute to sender reputation including consistency in sending patterns, authentication, list hygiene, engagement, complaint rates, and infrastructure setup. Drastic changes in any of these will negatively impact sender score.

February 2023 - Word to the Wise
Expert view

Expert from Email Geeks finds Sender Score relatively useful for root cause research of troubles that a dedicated IP might be having.

October 2021 - Email Geeks
Expert view

Expert from Email Geeks says the IP address appears to be a Klaviyo shared IP and that the score seems to be recovering.

February 2024 - Email Geeks
Expert view

Expert from Email Geeks shares a link showing the IP address has a lot of blocklistings, which could be related to the sender score issue.

September 2024 - Email Geeks
Expert view

Expert from Spam Resource answers that sender reputation can be affected if your emails suddenly start landing in spam folders, your open rates plummet, or you get blacklisted. This is a bad sign and potentially you have underlying problems

September 2023 - Spam Resource

What the documentation says
3Technical articles

Sender Score is influenced by various factors, including complaint rates, blacklist status, sending volume, spam traps, and sending to unknown users. Bounces and spam complaints negatively affect sender reputation. Preventing emails from being blocked requires email authentication (SPF, DKIM, DMARC), maintaining low spam rates, following sender guidelines, and utilizing feedback loops to monitor complaints, as well as maintaining list hygiene.

Key findings

  • Complaint Rates: High complaint rates significantly reduce Sender Score.
  • Blacklist Status: Being on external blacklists negatively impacts email deliverability and Sender Score.
  • Sending Volume: Inconsistent or sudden spikes in sending volume can lower Sender Score.
  • Spam Traps: Hitting spam traps damages sender reputation and lowers Sender Score.
  • Bounces: High bounce rates negatively impact sender reputation.
  • Authentication: SPF, DKIM and DMARC are important to maintain deliverability.

Key considerations

  • Monitor Complaint Rates: Implement feedback loops to monitor and address spam complaints.
  • Maintain List Hygiene: Regularly clean email lists to remove inactive and invalid addresses.
  • Authenticate Email: Ensure proper configuration of SPF, DKIM, and DMARC to authenticate email.
  • Low Spam Rates: Follow Google's Guidelines to prevent your emails from being blocked by Gmail users.
Technical article

Documentation from Validity Support explains that Sender Score is influenced by various factors including complaint rate, external blacklist status, sending volume, sending to spam traps, and unknown users. A high complaint rate and blacklisting impact the score negatively.

February 2025 - Validity Support
Technical article

Documentation from SparkPost explains that sender reputation is key and is affected by bounces, spam complaints and spam trap hits. They suggest using feedback loops to monitor complaints, and list hygiene to manage bounces.

August 2023 - SparkPost
Technical article

Documentation from Google explains that to prevent your emails from being blocked for Gmail users, authenticate your email with SPF, DKIM, and DMARC. Maintain low spam rates, and follow Gmail's sender guidelines.

July 2022 - Google