How do user spam reports, delivery errors, and domain reputation relate and what affects domain reputation?
Matthew Whittaker
Co-founder & CTO, Suped
Published 3 May 2025
Updated 17 Aug 2025
8 min read
Understanding how user spam reports, delivery errors, and your domain's reputation are interconnected is fundamental to achieving high email deliverability. It's not just about sending emails, it's about how mailbox providers, like Google, perceive your sending practices. A healthy domain reputation ensures your messages land in the inbox, while a poor one can lead to emails consistently being sent to the spam folder or even outright rejected.
This intricate relationship dictates whether your email campaigns succeed or fail. It is a dynamic system, constantly evaluating your sending behavior based on numerous signals. Let's explore how these factors influence each other and what you can do to maintain a strong sending reputation.
How user feedback shapes your domain reputation
At the heart of your domain's trustworthiness is how recipients interact with your emails, especially when it comes to marking them as spam. User spam reports are one of the most significant indicators to mailbox providers that your emails might be unwanted or irrelevant. Even a small percentage of users marking your emails as spam can severely damage your domain reputation.
Each spam complaint (also known as a junk mail complaint) sends a strong negative signal. Mailbox providers like Yahoo and Outlook closely monitor this metric. For instance, Google recommends keeping your spam rate below 0.3%, ideally under 0.1%, to ensure optimal inbox placement. A higher rate signals to them that your mail may be unwanted, leading to more emails being routed to the spam folder. You can learn more about this by reading how spam reports affect email domain reputation.
The negative impact of spam reports can spread, affecting not only your current campaigns but also the overall perception of your domain. Mailbox providers are increasingly sophisticated in detecting unwanted mail, and user feedback is a crucial component of their filtering algorithms. Ignoring these signals can result in your domain being placed on blocklists (or blacklists), severely impeding your ability to reach recipients.
Understanding delivery errors and their impact
Beyond explicit spam complaints, various delivery errors play a significant role in shaping your domain reputation. These errors, such as hard bounces (invalid email addresses), soft bounces (temporary issues like full inboxes), and temporary failures (TempFails), indicate problems with your sending practices or list quality. Consistent errors signal to mailbox providers that you might be sending to unengaged or outdated lists, which can negatively impact your sender trustworthiness.
For example, repeated hard bounces suggest poor list hygiene and can quickly tarnish your reputation. Similarly, high volumes of temporary failures, often due to rate limiting, can indicate that you are overwhelming a server or that your sending volume is perceived as suspicious. Mailbox providers interpret these signals as a lack of care in your sending practices. Learn more about how bounces and phishing attacks affect deliverability.
While some delivery errors are temporary, a persistent pattern of errors suggests underlying issues that can lead to a long-term decline in your domain reputation. Mailbox providers might start to filter your emails more aggressively, sending them to spam or blocking them entirely, even if your content is relevant. Proactive list cleaning and careful sending volume management are crucial to mitigate these risks.
Positive signals
High engagement: Consistent opens, clicks, and replies from your subscribers demonstrate genuine interest in your content.
Low bounce rates: Regularly cleaning your list to remove invalid or inactive addresses helps maintain low bounce rates.
Strong authentication: Properly configured SPF, DKIM, and DMARC records verify your sender identity.
Negative signals
High spam complaints: Recipients marking your emails as spam is the most damaging signal.
Frequent delivery errors: High bounce rates, temporary failures, or rate limiting issues indicate problems.
Low engagement: A lack of opens, clicks, or responses suggests recipients are not interested.
What influences your domain's trustworthiness
Domain reputation is a comprehensive score based on numerous variables, not just spam reports and delivery errors. Mailbox providers analyze a wide array of signals to determine your domain's trustworthiness. Understanding these factors is key to proactive reputation management.
First, engagement metrics are critical. High open rates, click-through rates, and replies demonstrate that your subscribers value your content. Conversely, low engagement or a high unsubscribe rate can negatively impact your reputation. Maintaining a clean, engaged list is paramount. Second, list quality is vital. Sending to unengaged users or, worse, to spam traps, can quickly plummet your domain's score. Regularly cleaning your list and using a double opt-in process can mitigate this risk. You can learn more about how email sending practices impact domain reputation.
Third, your email content matters. Spammy keywords, excessive images, broken links, or misleading subject lines can trigger filters and lead to spam complaints. Ensure your content is relevant, valuable, and consistent with your brand. Fourth, email authentication protocols like SPF, DKIM, and DMARC are crucial. Proper configuration of these records verifies your sender identity, proving to mailbox providers that your emails are legitimate and not spoofed. Mailchimp highlights how being labeled a spammy sender can even lead to your domain being blocklisted, meaning emails won't be delivered. You can find a simple guide on DMARC, SPF, and DKIM on our site.
Finally, your sending infrastructure (including your IP and domain history) and sending volume consistency also impact your reputation. Erratic sending patterns or sudden spikes in volume can raise red flags. A steady, predictable sending volume helps build trust. Domain reputation often outweighs IP reputation in the eyes of many ISPs.
If your domain reputation has suffered, the recovery process requires patience and a strategic approach. The first step is to definitively identify the root cause of the decline. Was it a sudden spike in spam complaints, a high bounce rate from an uncleaned list, or authentication failures? Analyzing data from your email service provider and tools like Google Postmaster Tools is essential. Our guide to improving domain reputation with Google Postmaster Tools can assist with this.
Once the root cause is identified, implement corrective actions. This often involves rigorous list cleaning, refining your segmentation to target only highly engaged subscribers, and adjusting sending volumes. Instead of broad broadcasts, consider sending to smaller, more responsive segments initially. Focus on delivering relevant content that encourages positive engagement like opens and clicks, and minimizes spam reports. This strategic approach helps to gradually rebuild trust with mailbox providers.
Consistency is crucial during the recovery phase. Stick to your improved sending practices, even if you don't see immediate results. Reputation recovery can take weeks or even months, depending on the severity of the damage. For instance, Gmail reputation-based bounces indicate a suspicious message, meaning you'll need to keep an eye on them. Monitor your metrics closely, looking for improvements in inbox placement, engagement rates, and a reduction in spam complaints and delivery errors. The consistency of positive signals is what ultimately sways mailbox providers to reassess your domain's standing. You can also review our guide on how long it takes to recover domain reputation for more insights.
Views from the trenches
Best practices
Maintain an email list hygiene routine by regularly removing inactive or invalid addresses to prevent bounces and maintain engagement.
Focus on delivering highly relevant content to segmented audiences to boost engagement and reduce spam complaints.
Implement and monitor all email authentication protocols: SPF, DKIM, and DMARC to build trust.
Gradually increase sending volume, especially after a period of low reputation, rather than sending large broadcasts.
Common pitfalls
Ignoring Google's spam rate guidelines (0.3% maximum, 0.1% ideal) can quickly lead to reputation degradation.
Failing to address the root cause of reputation drops means issues will likely recur even with temporary fixes.
Not segmenting your audience and sending irrelevant content increases spam complaints and disengagement.
Over-relying on a single external data point like Google Postmaster Tools without checking internal metrics.
Expert tips
Your overall understanding of product-market fit, verifiable campaign metrics, list integrity, and segmentation logic is more useful than any single external data point for long-term success.
For bad domain reputations, consider pausing sending for a while or using advanced segmentation tactics to target highly engaged users.
Monitor external data points for root cause analysis, particularly bounce, click, and complaint changes on your sending platform.
If external metrics show good engagement and conversion, your Google Postmaster Tools data might not fully reflect your actual performance.
Expert view
Expert from Email Geeks says that delivery errors can sometimes be unrelated to reported spam, such as issues with suspect attachments. For recipient spam votes, the goal is to keep the rate below 0.3%, ideally under 0.1%, to stay in the inbox. Domain reputation heavily influences inbox placement, more so than IP reputation, though IP reputation remains important. If you are in Google's bad books, the first step is to identify and correct the root cause, then resume sending at lower volumes while monitoring results.
2024-05-01 - Email Geeks
Expert view
Expert from Email Geeks says that focusing on external data points is necessary for identifying the root cause of deliverability issues, especially analyzing trends in bounce, click, and complaint changes on the sending platform.
2024-05-01 - Email Geeks
Maintaining a strong email sending identity
Your domain reputation is the bedrock of successful email deliverability. It is intricately linked to user spam reports and delivery errors, serving as a dynamic measure of how trustworthy mailbox providers deem your sending practices. Every interaction, positive or negative, contributes to this score, directly influencing whether your emails reach the inbox or are filtered out as spam.
Proactive management, consistent adherence to best practices, and diligent monitoring of your email metrics are essential for building and maintaining a strong reputation. By prioritizing subscriber engagement, maintaining clean lists, ensuring proper authentication, and being mindful of your sending patterns, you can cultivate a positive email sending identity that ensures your messages consistently reach their intended recipients.
Google, perceive your sending practices. A healthy domain reputation ensures your messages land in the inbox, while a poor one can lead to emails consistently being sent to the spam folder or even outright rejected.
Yahoo and 
Outlook closely monitor this metric. For instance, Google recommends keeping your spam rate below 0.3%, ideally under 0.1%, to ensure optimal inbox placement. A higher rate signals to them that your mail may be unwanted, leading to more emails being routed to the spam folder. You can learn more about this by reading how spam reports affect email domain reputation.
Google Postmaster Tools is essential. Our guide to improving domain reputation with Google Postmaster Tools can assist with this.
