How to identify the cause of a sudden spam complaint spike in Google Postmaster Tools when Klaviyo uses the same identifier for every email?

Summary

Identifying the cause of a sudden spam complaint spike in Google Postmaster Tools when Klaviyo uses the same identifier for every email requires a multi-faceted approach. Start by examining the identifiers Google uses within Postmaster Tools. Supplement this with data from other Feedback Loops (FBLs) like Yahoo and Microsoft to determine if the spike is isolated to Gmail or a broader issue. Be aware that Google's machine learning can influence Feedback ID selection. Monitor IP reputation using tools like Sender Score and check for changes in email content, subject lines, and preview text that might trigger spam filters. Ensure proper list hygiene by re-engaging inactive subscribers or removing them, and follow a gradual warm-up schedule when increasing sending volume. Verify domain authentication (SPF, DKIM, DMARC) and CAN-SPAM compliance. Regularly review and update suppression lists and A/B test your emails.

Key findings

  • Google Identifiers: Check identifiers used by Google Postmaster Tools.
  • Multiple FBLs: Analyze complaint data from other FBLs (Yahoo, Microsoft) to assess the scope.
  • Feedback ID Influence: Google's ML can independently choose Feedback IDs.
  • IP Reputation: Monitor IP reputation with tools like Sender Score; a drop correlates with complaints.
  • Content Changes: Review email content, subject lines, and preview text for triggers.
  • List Engagement: Unengaged subscribers lead to complaints; re-engage or remove them.
  • Sending Volume: Lack of warm-up when increasing volume triggers complaints.
  • Authentication: Incorrect SPF, DKIM, DMARC records flag emails as spam.
  • Suppression Lists: Outdated lists increase complaint rates.
  • CAN-SPAM: CAN-SPAM violations can lead to increased complaints.
  • A/B Testing: Problems can stem from email content that is of poor quality or not resonating with your audience.

Key considerations

  • Investigate Google Data: Use Google Postmaster Tools for specific identifiers.
  • Gather Cross-Provider Data: Collect data from multiple FBLs for a broader perspective.
  • Understand ML Influence: Acknowledge the influence of Google's algorithms.
  • Monitor Reputation: Regularly monitor IP and domain reputation.
  • Review Content: Regularly review your email for bad quality email that users will report.
  • Improve List Practices: Implement solid list hygiene practices (re-engagement, removal).
  • Follow Warm-Up Schedule: Use gradual warm-up procedures when scaling.
  • Verify Authentication: Ensure SPF, DKIM, and DMARC configuration.
  • Maintain Lists: Keep suppression lists updated.
  • Comply With Can-Spam: Compliance with CAN-SPAM regulations.
  • A/B Testing: All changes should be A/B tested to check results.

What email marketers say
9Marketer opinions

A sudden spam complaint spike in Google Postmaster Tools, particularly when using Klaviyo with non-unique identifiers, can stem from various factors. These include issues with IP reputation, problematic email content (keywords, formatting, excessive images), sending to unengaged or stale email list segments, and a lack of proper warm-up when increasing sending volume. Other causes can include changes to email authentication records (SPF, DKIM, DMARC), problematic subject lines or preview text, failure to adhere to CAN-SPAM regulations, and releasing a badly crafted email that didn't resonate with the audience. Regular A/B testing should prevent bad emails being released to the market.

Key opinions

  • IP Reputation: A drop in IP reputation can correlate with spam complaints. Monitor using tools like Sender Score.
  • Content Issues: Problematic keywords, excessive images, or formatting changes in email content can trigger spam filters.
  • List Engagement: Sending to unengaged or stale segments can lead to complaints. Re-engage or remove inactive subscribers.
  • Sending Volume: Increasing sending volume without proper warm-up can cause a spike.
  • Authentication: Incorrect or missing SPF, DKIM, and DMARC records can lead to emails being flagged as spam.
  • Subject Lines/Preview Text: Spammy subject lines or preview text can increase complaints.
  • CAN-SPAM: Non-compliance with CAN-SPAM regulations can lead to increased complaints.
  • A/B Testing: Ensure you A/B test email for negative effects of email.

Key considerations

  • Monitor Reputation: Regularly monitor IP and domain reputation to identify potential issues early.
  • Review Content: Carefully review email content, including subject lines and preview text, for potentially problematic elements.
  • Segment Lists: Segment email lists based on engagement and tailor content accordingly.
  • Warm-Up Schedule: Implement a gradual warm-up schedule when increasing sending volume or using new IPs/domains.
  • Verify Authentication: Ensure SPF, DKIM, and DMARC records are correctly configured.
  • Comply with Regulations: Adhere to CAN-SPAM regulations, including providing a clear unsubscribe link.
  • A/B Test Emails: Continuously A/B test email contents to catch if there are issues with the emails you are sending.
Marketer view

Email marketer from ActiveCampaign explains that ensure your email adheres to CAN-SPAM regulations. This includes having a clear unsubscribe link, valid return address, and accurate 'from' information. Non-compliance can lead to increased complaints.

March 2024 - ActiveCampaign
Marketer view

Email marketer from Mailjet explains that changes in email content can trigger spam filters. Reviewing recent email templates for potentially problematic keywords, excessive use of images, or changes in formatting can help identify the cause of the spike.

April 2023 - Mailjet
Marketer view

Email marketer from Litmus shares that subject lines play a big role in spam filtering. Analyse your recent subject lines for anything that might be deemed a spam keyword or phrased as clickbait, and maybe even a change in wording or the addition of an emoji may be enough to trigger a large spam response.

June 2024 - Litmus
Marketer view

Email marketer from Sendgrid explains that you should A/B test your email. You could have accidently released a very bad email into the market which resulted in a very bad response from users.

August 2024 - Sendgrid
Marketer view

Email marketer from Gmass explains that similarly to subject lines, preview text is important. An unexpected change can trigger spam filters and lead to a spike in complaints.

December 2021 - Gmass
Marketer view

Email marketer from StackOverflow explains that a significant increase in sending volume without proper warm-up can lead to a spam complaint spike. Gradually increasing sending volume, especially when introducing new IPs or domains, is crucial for maintaining a good sender reputation.

October 2024 - StackOverflow
Marketer view

Email marketer from Reddit suggests that a sudden spam complaint spike could be due to sending to an unengaged or stale segment of your email list. Re-engaging inactive subscribers or removing them from your list can improve your sender reputation.

February 2025 - Reddit
Marketer view

Email marketer from EmailGeek forum explains that check for any changes to your domain's SPF, DKIM, and DMARC records. Incorrect or missing authentication records can cause emails to be flagged as spam, leading to increased complaints.

August 2024 - EmailGeek Forum
Marketer view

Email marketer from Neil Patel's Blog suggests monitoring IP reputation closely using tools like Sender Score. A sudden drop in IP reputation can correlate with a spam complaint spike. Investigating the IP's sending history and any recent changes in sending practices is crucial.

February 2023 - Neil Patel's Blog

What the experts say
5Expert opinions

Identifying the cause of a spam complaint spike in Google Postmaster Tools, especially when Klaviyo uses the same identifier for every email, involves several investigative steps. First, examine the specific identifiers Google uses by clicking on the date under the graph in Postmaster Tools. Secondly, broaden the scope beyond Gmail and check complaint data from other Feedback Loops (FBLs) like Yahoo and Microsoft, as a spike across multiple providers suggests a more widespread issue. Google's machine learning might also independently pick a Feedback ID. Consider the scope, a spike isolated to Gmail may suggest a Gmail specific issue, whilst a widespread spike implies a more general problem with content or audience. Finally, rigorous list hygiene is crucial; implement practices such as removing inactive subscribers, suppressing complainers, and using double opt-in.

Key opinions

  • Google Identifiers: Check identifiers Google uses by clicking on the date under the graph in Postmaster Tools.
  • Multiple FBLs: Check complaint data from other Feedback Loops (Yahoo, Microsoft, etc.) to see if the spike is widespread.
  • Feedback ID: Google's ML engine might independently select a Feedback ID.
  • Complaint Scope: A spike only in Gmail may suggest a Gmail-specific filtering issue.
  • List Hygiene: Poor list hygiene can lead to increased complaints.

Key considerations

  • Investigate Google's Data: Use Google Postmaster Tools to understand the specific identifiers involved.
  • Analyze Cross-Provider Data: Gather complaint data from multiple FBLs for a broader perspective.
  • Understand ML Influence: Be aware that Google's algorithms can influence Feedback ID selection.
  • Isolate Problem Scope: Determine if the issue is specific to Gmail or affects multiple providers.
  • Improve List Practices: Implement rigorous list hygiene practices to reduce complaints.
Expert view

Expert from Email Geeks directs Tabish to click on the date under the graph in Google Postmaster Tools to see the identifiers Google used, which could help in identifying the cause of the issue.

May 2021 - Email Geeks
Expert view

Expert from Word to the Wise explains that rigorous list hygiene practices are crucial for mitigating spam complaints. Regularly removing inactive subscribers, suppressing complainers, and implementing a double opt-in process can help maintain a healthy sender reputation. They recommend segmenting lists based on engagement and sending targeted content to active users to minimize the risk of complaints.

March 2022 - Word to the Wise
Expert view

Expert from Spamresource emphasizes the importance of closely monitoring complaint feedback loops (FBLs) from various ISPs, not just Gmail. A spike in complaints across multiple FBLs suggests a widespread issue, potentially related to recent changes in email content, audience targeting, or sending practices. Conversely, a spike isolated to Gmail may point to issues specific to Gmail's spam filtering algorithms.

July 2024 - Spamresource
Expert view

Expert from Email Geeks suggests checking complaints from other Feedback Loops (FBLs) besides Google to see if there was a spike. They explain that other companies send complaint data back to ESPs like Klaviyo, and this data can help identify problematic emails by looking for corresponding spikes in complaints from places like Yahoo and Microsoft.

October 2023 - Email Geeks
Expert view

Expert from Email Geeks clarifies that while you can set the Feedback-ID, Google's ML engine might sometimes 'pick' a Feedback ID independently.

August 2024 - Email Geeks

What the documentation says
4Technical articles

When facing a sudden spam complaint spike in Google Postmaster Tools, and Klaviyo uses the same identifier, focus on broader data sources and list management. Participating in Feedback Loops (FBLs) offers insights into campaign-specific complaints, even with non-unique identifiers. Recognize that Message-IDs don't directly correlate with Google Postmaster Tool data, and look to other identifiers instead. Use Microsoft's SNDS for a comparative view of complaint rates across providers to see if the issue is Gmail-specific. Lastly, maintain up-to-date suppression lists to remove unsubscribed or marked-as-spam users, as failing to do so raises complaint rates.

Key findings

  • Feedback Loops (FBLs): FBLs provide campaign-specific complaint data, even without unique identifiers.
  • Message-ID Irrelevance: Message-IDs do not directly correlate to data in Google Postmaster Tools.
  • Comparative Data: Microsoft SNDS offers data for comparison against Google's Postmaster Tools, revealing if the spike is Gmail-specific.
  • Suppression Lists: Outdated suppression lists lead to increased complaint rates.

Key considerations

  • Engage with FBLs: Actively participate in FBLs to identify problematic campaigns or patterns.
  • Focus on Other Identifiers: When troubleshooting, focus on identifiers other than Message-IDs.
  • Utilize SNDS: Use Microsoft SNDS to compare complaint data across different providers.
  • Maintain Lists: Regularly update suppression lists to remove users who have opted out or reported spam.
Technical article

Documentation from RFC states that while message-id's are important for email tracking, they don't directly correlate with Google Postmaster Tool data. Suggests looking into other identifiers.

February 2025 - RFC
Technical article

Documentation from Microsoft states that using SNDS (Smart Network Data Services) can provide data on complaint rates specific to their users, offering a comparative perspective to Google's Postmaster Tools. Analyzing SNDS data might reveal if the spike is isolated to Gmail or affects other mailbox providers as well.

August 2022 - Microsoft
Technical article

Documentation from Sparkpost emphasizes regularly reviewing and updating your suppression lists to exclude users who have unsubscribed or previously marked emails as spam. A failure to suppress these users can contribute to increased complaint rates.

June 2024 - Sparkpost
Technical article

Documentation from Google Support explains that participating in feedback loops (FBLs) can provide insights into spam complaints. By analyzing FBL data, senders can identify specific campaigns or email patterns that are generating higher-than-usual complaint rates, even when identifiers are not unique.

November 2022 - Google Support