How do I identify who reported my emails as spam in Gmail and how to reduce complaints?
Matthew Whittaker
Co-founder & CTO, Suped
Published 26 Jun 2025
Updated 16 Aug 2025
6 min read
Email marketers often face the challenge of understanding why their emails land in the spam folder, particularly when it comes to complaints. A common question I encounter is how to identify exactly who reported an email as spam in Gmail. It's a critical piece of information that can help refine email strategies and maintain a healthy sender reputation.
While it is not possible to pinpoint individual users who mark your emails as spam in Gmail, understanding aggregate data and implementing effective strategies can significantly reduce your overall spam complaint rate. This article will guide you through managing complaints and improving your email deliverability.
Understanding Gmail's approach to spam complaints
Unlike some other mailbox providers, Gmail does not offer a traditional Feedback Loop (FBL) service that identifies the specific email addresses of users who report your messages as spam. This approach is primarily due to privacy concerns. Instead, Gmail focuses on providing aggregated data to help senders understand their overall performance.
When a user clicks the “Report spam” button, it signals to Gmail’s algorithms that the content was unwanted. This action contributes to your domain’s sender reputation and affects how future emails are delivered. A high number of spam reports can lead to your emails consistently landing in the spam folder, or even being blocked entirely.
The key takeaway here is that while you can’t get individual details, the collective actions of your recipients are clearly visible through metrics. This aggregate data is what you need to focus on for improvements and to recover Gmail email deliverability.
Leveraging Google Postmaster Tools
The primary tool for monitoring your sender reputation and spam complaint rates with Gmail is Google Postmaster Tools. This free service provides valuable insights into your email performance across various metrics, including your spam rate. While it doesn't show individual complaints, it aggregates data, allowing you to identify trends and potential issues impacting your deliverability. You can learn more about how to identify users generating spam complaints via Postmaster Tools.
Postmaster Tools provides data on your domain’s reputation (good, medium, low, bad) and IP reputation, which are both heavily influenced by spam complaints. A sudden spike in complaints, even without knowing the source, indicates a problem with your email content, audience targeting, or sending practices.
Accessing your spam rate in Postmaster Tools
To view your spam complaint rate and other relevant metrics:
Verify your domain: First, you need to verify your sending domain in Google Postmaster Tools.
Monitor spam rate: Once verified, navigate to the Spam Rate dashboard. This shows the percentage of your emails marked as spam by Gmail users over a selected period.
Reputation dashboards: Also check the IP Reputation and Domain Reputation sections to understand your overall sending health. These metrics are critical for inbox placement.
Google aims for a spam complaint rate below 0.1%. If your rate approaches or exceeds 0.3%, it can severely impact your deliverability, leading to more emails landing in the spam folder or being rejected. Keeping this rate as low as possible is paramount for maintaining a healthy sender reputation and avoiding high spam complaint rates.
Strategies to reduce spam complaints
Since identifying individual complainers isn't an option, your focus should shift to implementing proactive strategies to prevent spam complaints. A low complaint rate is a strong signal of engaged subscribers and good sending practices. Spam complaints are often a symptom of underlying issues in your email program.
Best practices for email marketing
Permission-based lists: Only send to recipients who have explicitly opted into receiving your emails. Double opt-in is highly recommended.
Clear unsubscribe options: Make it easy for subscribers to opt out. A prominent unsubscribe link reduces the likelihood of them marking your email as spam (or on a blocklist / blacklist).
Relevant content: Ensure your email content is valuable and relevant to your audience's interests and expectations based on their subscription.
Consistent sending: Maintain a consistent sending schedule so subscribers know when to expect your emails.
Common pitfalls that cause complaints
Purchased lists: Sending to purchased, scraped, or old lists leads to high bounce rates and spam complaints, severely damaging your reputation.
Hidden unsubscribe links: Making it hard to unsubscribe frustrates recipients, causing them to report spam out of frustration.
Irrelevant content: Sending content that doesn't align with subscriber expectations increases the likelihood of complaints.
Infrequent sending: If you send emails too infrequently, subscribers may forget they opted in and mark your emails as spam.
Maintaining a clean and engaged email list is crucial. Regularly remove inactive subscribers who haven't opened or clicked your emails in a long time. These unengaged users are more likely to mark your messages as spam, even if they initially opted in. Email service providers (ESPs) often provide tools to track spam complaints and help with list hygiene.
Beyond content, ensuring your email authentication records are correctly configured is fundamental. This includes SPF, DKIM, and DMARC. These records verify that your emails are legitimately from your domain, which is a major factor in how mailbox providers like Gmail perceive your sending practices. A simple guide to DMARC, SPF, and DKIM can help you set these up correctly.
Example of a clear unsubscribe link and headerHTML
<a href="https://yourdomain.com/unsubscribe" style="color: #007bff; text-decoration: underline;">Unsubscribe from this list</a>
List-Unsubscribe: <mailto:unsubscribe@yourdomain.com?subject=unsubscribe>, <https://yourdomain.com/unsubscribe>
Finally, ensure your emails adhere to Gmail's bulk sender guidelines, particularly the new requirements. These guidelines cover authentication, spam rates, and easy unsubscription, all of which directly impact your ability to reach the inbox. Ignoring them can cause your emails to go to spam (or get you on a blacklist).
Re-engagement and suppression strategies
Even with the best practices, some subscribers may become disengaged over time. Instead of waiting for them to mark your emails as spam, consider implementing re-engagement campaigns. These campaigns are designed to rekindle interest and give subscribers an explicit opportunity to update their preferences or unsubscribe.
For subscribers who remain unresponsive after re-engagement efforts, it's often best to remove them from your active sending list. While it might seem counterintuitive to reduce your list size, suppressing unengaged users protects your sender reputation and improves your overall deliverability. This is a key aspect of managing email spam complaints and unsubscriptions.
Subscriber status
Recommended action
Active (opens, clicks)
Continue sending engaging content.
Inactive (no engagement in 30-60 days)
Initiate a re-engagement campaign.
Unresponsive (no engagement after re-engagement)
Suppress or remove from mailing list to protect reputation.
While you cannot identify who specifically reported your emails as spam in Gmail, the aggregated data provided by Google Postmaster Tools is an invaluable resource. By focusing on your overall spam rate and other reputation metrics, you can diagnose issues and implement effective solutions.
Ultimately, reducing spam complaints is about sending relevant emails to engaged subscribers and adhering to email best practices. This includes robust email authentication, clear unsubscribe options, and proactive list hygiene. By prioritizing these areas, you'll not only reduce complaints but also significantly improve your overall email deliverability.
Views from the trenches
Best practices
Regularly clean your email lists to remove inactive or unengaged subscribers.
Make your unsubscribe link highly visible and easy to use in every email.
Send targeted and relevant content to specific segments of your subscriber list.
Track open rates, click-through rates, and bounces to identify potential issues early.
Common pitfalls
Failing to process unsubscribe requests promptly can lead to increased spam complaints.
Irrelevant or unengaging content prompts recipients to mark emails as spam.
Using purchased email lists or very old, unverified lists often results in high complaint rates.
Lack of proper SPF, DKIM, and DMARC records can negatively impact deliverability and increase spam flagging.
Expert tips
Google Postmaster Tools provides critical aggregate data on your domain's sending reputation and spam complaint rates.
Implement strategies to re-engage inactive subscribers, offering them a clear choice to stay or leave.
Before sending, test your email content with spam checker tools to identify potential triggers.
Remind subscribers why they are receiving your emails and how to manage their preferences.
Expert view
Expert from Email Geeks says that Google does not provide an official Feedback Loop (FBL) that would allow senders to identify individual users who mark emails as spam.
2022-07-19 - Email Geeks
Marketer view
Marketer from Email Geeks says that while individual spam complaints in Gmail cannot be tracked, monitoring aggregate complaint rates in Google Postmaster Tools is crucial for maintaining low complaint volumes.
