Why are Google Postmaster Tools spam rates suddenly spiking?

Summary

Sudden spikes in Google Postmaster Tools spam rates are multifaceted, reflecting a complex interplay of factors impacting email deliverability. These include a declining sender reputation potentially leading to bulk foldering, Google's refined spam rate calculations focusing on 'active users,' which amplifies the impact of inactive subscribers, changes in sending practices, problematic content, inadequate email authentication (SPF, DKIM, DMARC), poor IP reputation, and neglecting list hygiene. Email marketers should continuously monitor their sending practices, prioritize email authentication, maintain stringent list hygiene by removing unengaged users, and ensure that their email content is not triggering spam filters.

Key findings

  • Reputation Decline: Spam rate spikes often signal a pre-existing decline in sender reputation, culminating in bulk foldering by Gmail.
  • Active User Emphasis: Google's spam rate calculation prioritizes active users, magnifying the impact of sending to inactive or unengaged recipients.
  • Authentication Importance: Proper email authentication through SPF, DKIM, and DMARC is crucial to prevent sender spoofing and improve deliverability.
  • List Hygiene Impact: Poor list hygiene, including sending to unengaged or outdated email addresses, significantly contributes to elevated spam rates.
  • Content Triggers: Specific keywords, formatting issues, and suspicious links within email content can inadvertently trigger spam filters.

Key considerations

  • Investigate Changes: Thoroughly examine any recent modifications in sending practices, content creation, or list management to pinpoint potential causes.
  • Prioritize Active Users: Shift focus toward engaging active subscribers and actively removing inactive recipients to improve deliverability metrics.
  • Monitor Performance: Continuously monitor feedback loops, unsubscribe rates, and Google Postmaster Tools data to identify emerging issues.
  • Maintain List Hygiene: Implement consistent list cleaning practices, including identifying and removing unengaged or invalid email addresses.
  • Test and Refine Content: Utilize spam filter testing tools to assess email content and refine language, formatting, and links to minimize the risk of triggering filters.

What email marketers say
9Marketer opinions

Sudden spikes in Google Postmaster Tools spam rates can stem from various factors. These include changes in sending practices, content, or recipient lists; list hygiene issues such as sending to unengaged addresses; poor IP reputation; missing email authentication; spammy content; purchased lists; and other factors. Addressing these issues requires continuous monitoring, list cleaning, email authentication, content review, and deliverability testing.

Key opinions

  • List Hygiene: Sending to old or unengaged addresses is a major contributor to spam complaints. Regular list cleaning is essential.
  • Content Triggers: Changes in email content, including keywords, formatting, and links, can trigger spam filters.
  • Email Authentication: Missing or incorrect SPF, DKIM, and DMARC records can negatively impact deliverability.
  • IP Reputation: A poor IP reputation can lead to increased spam rates. Monitoring and improving IP reputation are crucial.
  • Sudden Changes: Spikes often correlate with changes in sending frequency, volume, or the introduction of new recipient segments.

Key considerations

  • List Segmentation: Segment lists to send relevant content to specific groups, increasing engagement.
  • Deliverability Testing: Regular testing helps identify and address deliverability issues before they impact your sending reputation.
  • Avoid Purchased Lists: Never use purchased email lists, as they lead to high bounce rates, spam complaints, and damage to sender reputation.
  • Monitor Feedback Loops: Actively monitor feedback loops and unsubscribe rates to identify and address issues proactively.
  • Review Sending Practices: Evaluate recent changes in sending frequency, volume, and recipient demographics to identify potential causes of spam rate spikes.
Marketer view

Email marketer from StackExchange answers that poor IP reputation can lead to deliverability issues, including increased spam rates. They recommend monitoring IP reputation using tools like Google Postmaster Tools and working with your ESP to improve it.

October 2024 - StackExchange
Marketer view

Email marketer from Mailjet explains that you should improve your sender reputation by consistently authenticating emails (SPF, DKIM, DMARC), segmenting lists to send relevant content, and regularly cleaning your email list to remove unengaged recipients.

August 2024 - Mailjet
Marketer view

Email marketer from Email Geeks shares questions to consider, such as whether inboxing has just started, if there was significant send volume, if DKIM was enabled on new streams, and if volume has changed to give Gmail more data.

May 2022 - Email Geeks
Marketer view

Email marketer from EmailOctopus Blog shares that a sudden increase in spam complaints may be caused by list hygiene problems (sending to old or unengaged addresses), changes in email content that trigger spam filters, or sending to newly acquired lists without warming them up.

August 2024 - EmailOctopus Blog
Marketer view

Email marketer from Litmus explains that spam filters analyze email content for certain keywords, formatting issues, and suspicious links. They recommend avoiding overly promotional language, using a reasonable link-to-text ratio, and testing your emails with spam filter tools before sending.

August 2024 - Litmus
Marketer view

Email marketer from Sender explains that list cleaning involves removing inactive subscribers and email addresses from your contact list, improving your deliverability metrics. The advice is to filter and delete unengaged subscribers who haven't opened your emails in a certain period of time.

July 2023 - Sender.net
Marketer view

Email marketer from ZeroBounce explains that using purchased email lists is highly detrimental to deliverability, as these lists often contain outdated or invalid addresses, and recipients are unlikely to have opted in to receive your emails. This leads to high bounce rates, spam complaints, and damage to your sender reputation.

November 2022 - ZeroBounce
Marketer view

Email marketer from GlockApps explains that several factors can cause emails to land in the spam folder, including poor list quality, missing or incorrect authentication records, spammy content, and high complaint rates. Regular deliverability testing can help identify these issues.

July 2021 - GlockApps
Marketer view

Email marketer from Reddit shares that sudden spikes might come from changes in sending frequency, content, or the recipient list. They suggest checking recent email campaigns for problematic elements (links, keywords) and monitoring the unsubscribe rate.

May 2023 - Reddit

What the experts say
5Expert opinions

Sudden spikes in Google Postmaster Tools spam rates are often indicative of underlying deliverability issues. Factors contributing to these spikes include a declining sender reputation leading to bulk foldering, changes in how Google calculates spam rates focusing on active users, which exposes issues with inactive users on your list. The spikes are also associated with shifts in sending practices, problematic content, poor list hygiene, and low user engagement. It is important to note that Google doesn't publish a hard complaint rate threshold; the metrics are about reporting and overall reputation.

Key opinions

  • Declining Reputation: Spam spikes are often a late indicator of a longer-term decline in sender reputation.
  • Active User Calculation: Google's spam rate calculation now heavily emphasizes 'active users,' highlighting deliverability issues to inactive addresses.
  • Lack of Threshold: Google doesn't publish a specific complaint threshold, meaning the focus should be on overall reputation rather than a specific number.
  • Engagement Signals: Low user engagement, such as infrequent opens and clicks, negatively impacts deliverability.
  • List Hygiene: Poor list hygiene and sending to unengaged users contribute to spam complaints.

Key considerations

  • Investigate Changes: Investigate recent changes in sending practices, content providers, and links.
  • Target Active Users: Focus on targeting and engaging active users and removing inactive ones from your lists.
  • Monitor Feedback Loops: Monitor feedback loops and investigate any changes that might cause increased complaints.
  • Improve List Hygiene: Implement robust list hygiene practices to remove inactive users and maintain a healthy sender reputation.
  • Enhance Engagement: Prioritize user engagement through relevant content and personalized communication to keep users active and reduce spam complaints.
Expert view

Expert from Email Geeks clarifies that Gmail doesn't publish a complaint threshold and the change is in how they are reporting data, not a change in how they internally measure reputation. The expert also mentions how people are making statements about acceptable complaint rates and that 0.3% is the rate where deliverability issues start, rather than a hard-and-fast threshold.

March 2023 - Email Geeks
Expert view

Expert from Email Geeks, supported by marketer from Email Geeks, believes the Google Postmaster Tools spam rate calculation change involves 'active users,' meaning the spam rate is now calculated based on users who have actively engaged with their Gmail mailbox recently. The spike would indicate that the target contains too many inactive users.

April 2023 - Email Geeks
Expert view

Expert from Email Geeks explains that the spam rate spike is likely a signal that the sender's reputation has been falling and they've reached a threshold where Google is bulk foldering the mail. They advise checking for changes in links, CDNs, or new content providers that might be causing the issue.

October 2024 - Email Geeks
Expert view

Expert from Word to the Wise explains that low user engagement, like infrequent opens or clicks, signals to mailbox providers that your emails may not be relevant or desired, potentially leading to deliverability problems and increased spam rates. Keeping your lists engaged is key.

June 2021 - Word to the Wise
Expert view

Expert from Spamresource explains that several factors can cause a sudden increase in spam complaints, including changes in sending practices, content triggers, or a decline in list hygiene. They emphasize investigating recent changes and monitoring feedback loops.

April 2023 - Spamresource

What the documentation says
4Technical articles

The documentation highlights key aspects of email deliverability and security. Google defines spam rate as the percentage of user-marked spam emails divided by the total inbox deliveries, emphasizing its impact on sender reputation. SPF records are crucial for authenticating authorized mail servers, preventing 'From' address forgery. DMARC builds upon SPF and DKIM, enabling senders to specify handling policies for authentication failures. Microsoft's SNDS offers data on IP addresses and associated complaints, assisting in identifying and resolving deliverability issues. These technologies are designed to work together to improve email deliverability and trust.

Key findings

  • Spam Rate Definition: Spam rate directly impacts sender reputation and deliverability, defined as user-reported spam divided by inbox deliveries.
  • SPF Authentication: SPF records authorize mail servers, preventing 'From' address spoofing.
  • DMARC Policy: DMARC builds upon SPF and DKIM, allowing senders to specify policies for handling authentication failures.
  • SNDS Monitoring: Microsoft's SNDS provides data on IP address complaints, aiding in deliverability issue identification.

Key considerations

  • Implement SPF: Create and maintain accurate SPF records to authorize sending mail servers.
  • Implement DMARC: Deploy DMARC policies with appropriate handling instructions for authentication failures.
  • Monitor SNDS: Regularly monitor SNDS for complaint data related to your IP addresses.
  • Reduce Spam Rate: Actively work to reduce the spam rate by implementing email best practices like list hygiene and relevant content.
  • Authenticate Email: Implement comprehensive email authentication including SPF, DKIM, and DMARC.
Technical article

Documentation from Google Support explains that the spam rate is the percentage of emails marked as spam by users, divided by the number of emails sent to the inbox. A high spam rate can negatively impact sender reputation and deliverability.

October 2022 - Google Support
Technical article

Documentation from Microsoft answers that the SNDS (Smart Network Data Services) program provides data about your sending IP address and the volume of complaints associated with it. Monitoring SNDS can help identify and address deliverability problems.

September 2021 - Microsoft
Technical article

Documentation from DMARC.org explains that DMARC (Domain-based Message Authentication, Reporting & Conformance) is an email authentication protocol that allows senders to indicate that their emails are protected by SPF and DKIM, and tells receivers what to do if authentication fails, such as reject the message.

December 2024 - DMARC.org
Technical article

Documentation from RFC explains that SPF (Sender Policy Framework) records are DNS records that specify which mail servers are authorized to send email on behalf of your domain. Having a proper SPF record helps prevent spammers from forging your 'From' address.

September 2021 - RFC