Summary
Google Postmaster Tools calculates spam complaints using feedback from Gmail users, dividing the number of spam complaints by the number of emails delivered to inboxes to determine the spam rate. This rate, along with sender reputation, authentication, and sending volume, are key factors in determining email placement and deliverability. The tools aggregate and analyze user feedback, DMARC volume, and sending patterns to provide insights into sender reputation and identify campaigns generating high spam rates. It's important to compare spam rates with DMARC volume, monitor for sudden spikes, and address high complaint rates, especially on automated emails, as they may indicate list-bombing attacks. Google attributes spam reports to when the email was received, which may not be the same day it was sent. High complaint rates negatively influence sender reputation and can trigger spam filters.
Key findings
- Spam Rate Calculation: Spam rate is calculated by dividing the number of spam complaints by the number of emails delivered to inboxes.
- Multi-Factor Analysis: Google uses factors like spam complaints, sender reputation, and authentication to determine email placement.
- Feedback Loop: Google provides aggregated data about email traffic and spam complaints through the Feedback Loop (FBL).
- DMARC Volume: Comparing spam rates with DMARC volume is important for understanding the impact of complaints.
- Complaint Timing: Google attributes spam reports to when the email was received, not necessarily when it was sent.
- User Reports: Spam complaints are primarily based on user reports in Gmail.
Key considerations
- Monitor Spam Rate: Regularly monitor the spam rate in Google Postmaster Tools to identify potential issues.
- Authenticate Emails: Ensure proper email authentication (SPF, DKIM, DMARC) to improve sender reputation.
- Improve Sending Practices: Improve sending practices and email content to reduce user-reported spam complaints.
- Analyze Volume and Rate: Pay attention to both the volume and rate of complaints, as a high rate can be more damaging than a high volume.
- Address Complaint Spikes: Promptly address sudden spikes in spam complaints, as they may indicate underlying problems.
- Use Feedback Loop: Utilize the Feedback Loop to identify campaigns generating high spam rates.
- Consider Email Timing: Be mindful of the timing of email sends and potential impacts on complaint rates.
What email marketers say
14 marketer opinions
Google Postmaster Tools calculates spam complaints and volume using various factors, including user-reported spam, DMARC volume, and sending reputation. The spam rate is generally the number of spam complaints divided by the number of emails delivered to inboxes. High spam rates can negatively affect deliverability. Google also uses algorithms to analyze content, sending patterns, and user feedback to determine spam placement. The tools provide data on spam complaints, allowing senders to monitor their performance and identify potential issues. A high complaint rate can be a sign of list-bombing attacks or issues with email content or sending practices.
Key opinions
- Spam Rate Calculation: Google calculates the spam rate by dividing the number of spam complaints by the number of emails delivered to the inbox.
- DMARC Volume Comparison: Comparing spam rates with DMARC volume can provide valuable insights into the significance of spam complaints.
- Timing of Complaints: Complaints can be levied against emails sent the day before, and Google reports data based on when the events occurred.
- Volume and Rate Impact: High complaint rates on low volume days have less impact than moderate rates on high volume days.
- List-Bombing Indicator: High complaint rates on automated emails may indicate a list-bombing bot attack.
- Feedback Loop: Google aggregates user feedback to calculate spam complaints by comparing it to your sending volume.
- Multi-Factor Analysis: Google uses various factors like spam complaints, sender reputation, and authentication to determine email placement.
Key considerations
- Monitor Spam Rates: Regularly monitor spam rates in Postmaster Tools to identify sudden spikes or trends that may indicate deliverability issues.
- Analyze Sending Practices: Analyze sending practices and email content for potential issues that could be causing high spam complaints.
- Authentication Methods: Ensure proper email authentication (SPF, DKIM, DMARC) to improve sender reputation and reduce the likelihood of being marked as spam.
- Compare DMARC Volume: Always compare spam rates against reputed DMARC volume to understand the impact of complaints.
- Address High Complaint Rates: Address high complaint rates promptly, especially on automated emails, to prevent long-term deliverability damage.
- Be Aware of Complaint Timing: Understand that Google attributes spam reports to when the email was received, which may not be the same day it was sent.
- Monitor Reputation: Track sending volume and reputation over time, using historical performance and user feedback.
Marketer view
Email marketer from EmailGeeks Forum explains that the spam percentage in Postmaster Tools is calculated by dividing the number of emails marked as spam by the total number of emails delivered to Gmail inboxes. This provides insight into how users perceive your email.
28 Jun 2023 - EmailGeeks Forum
Marketer view
Email marketer from Email Geeks explains that it is entirely possible there were complaints levied against an email that was sent the day before, and that Google reports the data points during the time period in which they occurred.
14 Jan 2022 - Email Geeks
What the experts say
2 expert opinions
Google Postmaster Tools calculates spam complaints based on feedback from Gmail users who mark emails as spam. The tool aggregates this data to provide insights into sender reputation and deliverability. It also analyzes the percentage of emails marked as spam to assess reputation and inform deliverability decisions.
Key opinions
- Feedback Loop Data: Spam complaints are calculated using feedback loop data from Gmail users.
- Aggregated Insights: The aggregated data provides insights into sender reputation and deliverability.
- Percentage Analysis: The percentage of emails marked as spam is analyzed to assess sender reputation.
Key considerations
- Monitor Spam Complaints: Regularly monitor spam complaints in Google Postmaster Tools.
- Improve Email Practices: Improve email sending practices to reduce the number of spam complaints.
- Maintain Reputation: Maintain a good sender reputation to ensure better email deliverability.
Expert view
Expert from Word to the Wise shares that Google Postmaster Tools monitors spam complaints by analyzing the percentage of emails marked as spam by recipients. The tool uses this data to assess the sender's reputation and inform deliverability decisions.
17 Oct 2021 - Word to the Wise
Expert view
Expert from Spam Resource explains that Google Postmaster Tools calculates spam complaints based on the feedback loop data received from Gmail users who mark emails as spam. The tool aggregates this data to provide insights into the sender's reputation and deliverability.
24 Apr 2025 - Spam Resource
What the documentation says
3 technical articles
Google Postmaster Tools calculates spam complaints by dividing the number of spam complaints by the number of emails sent to the inbox, resulting in the spam rate. A high spam rate can negatively impact email deliverability. Google provides aggregated and anonymous data about email traffic, including spam complaints, through the Feedback Loop (FBL) to help senders identify campaigns generating high spam rates. They also use user reports to calculate spam complaints, offering insights into email sending reputation and other metrics to improve deliverability.
Key findings
- Spam Rate Calculation: Spam rate is the number of spam complaints divided by the number of emails sent to the inbox.
- Feedback Loop (FBL): Google provides aggregated, anonymous data on email traffic, including spam complaints, through the FBL.
- User Reports: Spam complaints are calculated based on user reports.
Key considerations
- Monitor Spam Rate: Regularly monitor the spam rate in Postmaster Tools to identify potential issues.
- Utilize Feedback Loop: Use the Feedback Loop to identify campaigns generating high spam rates.
- Improve Email Sending Practices: Improve email sending practices and content to reduce user-reported spam complaints.
Technical article
Documentation from Google Support shares that they provide aggregated, anonymous data about your email traffic, including spam complaints, through the Feedback Loop (FBL). The FBL helps senders identify campaigns that are generating high spam rates.
29 Jan 2025 - Google Support
Technical article
Documentation from Google Developers shares that Postmaster Tools provides insights into your email sending reputation, spam rate, and other key metrics to help you improve deliverability. They calculate spam complaints based on user reports.
18 Nov 2024 - Google Developers
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