How to recover email domain and IP reputation after a spam incident or large accidental send?
Matthew Whittaker
Co-founder & CTO, Suped
Published 25 Jun 2025
Updated 19 Aug 2025
9 min read
Experiencing a sudden drop in email deliverability or being hit by a spam incident can feel like a punch to the gut. Whether it was a large, accidental email send or a malicious spam attack, the impact on your domain and IP reputation can be severe. It can lead to your legitimate emails landing in spam folders or being outright rejected by major inbox providers. I've seen many businesses struggle to bounce back from such incidents, and it takes a structured approach to repair the damage.
The good news is that email reputation is not permanently broken. It can be rebuilt, but it requires immediate action, careful diagnosis, and a consistent commitment to best practices. Reputation is dynamic, constantly evaluated by mailbox providers based on your sending behavior and recipient engagement.
This guide outlines the essential steps to recover your email domain and IP reputation, helping you restore trust with inbox providers and ensure your emails reach their intended recipients.
Immediate actions after an incident
The very first thing you need to do is stop the bleeding. If an accidental send is ongoing, or if you suspect a breach, immediately halt all email sending from the affected domain or IP. Continuing to send will only worsen the damage and make recovery more challenging. This pause gives you crucial time to assess the situation without further harming your reputation.
Next, identify the root cause of the incident. Was it a misconfigured automation, a stolen credential, a poorly segmented list, or a direct spam attack? Understanding the cause is critical to preventing recurrence. For instance, if credentials were stolen, you'll need to secure your systems and change passwords immediately. If it was a list issue, you'll need to address your data hygiene processes.
During this initial phase, it's also wise to prepare for de-listing requests if your IP or domain ends up on a public blocklist. Many blocklists (or blacklists) provide a process for removal once the issue is resolved and you demonstrate improved sending practices. While this isn't a silver bullet, it's a necessary step in the recovery process, especially for widely used blacklists.
Urgent steps
Stop sending: Immediately cease all email transmissions from the affected domain and IP address.
Identify cause: Determine what led to the incident, whether it was a security breach, a marketing error, or a system misconfiguration.
Secure accounts: Change all compromised passwords and strengthen security protocols, especially for accounts with email sending permissions.
Diagnosing the damage to your reputation
Once you've stopped sending and identified the initial cause, your next step is to understand the extent of the damage. Google Postmaster Tools provides invaluable insights into your domain and IP reputation with Google (which accounts for a significant portion of email traffic). Here, you can check your spam rate, IP reputation, domain reputation, and authentication status. You can find more details on how to use these tools in our Ultimate Guide to Google Postmaster Tools.
Beyond Google, it's crucial to check if your domain or IP has landed on any public blocklists (sometimes called blacklists). While blocklist inclusion is a symptom, not the cause, it directly impacts deliverability. Many tools allow you to check this, and you can delve deeper into how email blacklists actually work for a comprehensive understanding. Knowing which blocklists you're on helps prioritize de-listing efforts.
Look for spikes in bounce rates (especially hard bounces), unsubscribe rates, and spam complaints. These metrics are direct indicators that your email list quality or content is problematic. A sudden increase in any of these suggests that your reputation has taken a hit, impacting your overall email deliverability. Pay particular attention to feedback loops from major inbox providers if you have them configured, as these can pinpoint specific issues.
The core of reputation recovery lies in cleaning your email list. A large accidental send often means you've hit a significant number of unengaged users, dormant accounts, or even spam traps. These non-responsive or malicious addresses severely damage your reputation. Immediately remove any hard bounces, invalid addresses, and disengaged subscribers from your lists. Consider using a reputable email validation service.
After the cleanup, focus on re-engaging your active subscribers. Start by sending to your most engaged segments (those who have opened or clicked recently). This signals to mailbox providers that you're sending desired content, which is crucial for rebuilding trust. Over time, you can gradually expand your sending volume to less engaged but still valid segments, but always monitor your metrics closely.
The content of your emails also plays a vital role. Ensure your emails are relevant, valuable, and free of spammy keywords or deceptive practices. Personalization and segmentation can significantly improve engagement and reduce the likelihood of spam complaints. A/B test your subject lines and calls to action to see what resonates best with your audience. Remember, a good sender reputation is built on consistent positive engagement from your recipients.
For severe cases, where your reputation is critically low, a temporary pause in sending to specific providers like Gmail might be necessary. This Gmail-specific recovery strategy allows their systems to reset your reputation score. During this period, focus intensely on cleaning your list and preparing high-quality, targeted campaigns for when you resume sending.
Additionally, implement a double opt-in process for all new subscribers. This verifies that new sign-ups are legitimate and genuinely interested in receiving your emails, significantly reducing the risk of hitting spam traps (or blocklists / blacklists) or receiving complaints down the line. It's a foundational practice for long-term list health and deliverability.
The problem: poor list quality
Unengaged users: Sending to recipients who haven't opened or clicked in a long time increases spam complaints.
Spam traps: Old, dormant, or malicious email addresses designed to catch spammers.
High bounces: Sending to non-existent addresses negatively impacts your sender reputation.
The solution: strategic list management
Aggressive cleanup: Remove all unengaged, inactive, and invalid addresses from your lists.
Double opt-in: Implement this for all new sign-ups to ensure genuine interest and valid addresses.
Re-engagement campaigns: Target your most active subscribers first, then gradually re-warm.
Implementing technical best practices
Proper email authentication is non-negotiable for deliverability. Ensure your SPF (Sender Policy Framework), DKIM (DomainKeys Identified Mail), and DMARC (Domain-based Message Authentication, Reporting & Conformance) records are correctly configured and aligned. A 0% SPF success rate, as seen in some instances, is a red flag that needs immediate attention. Even if your SPF record checks out with a basic tool, actual authentication can still fail due to misconfigurations or other underlying issues. Our guide on DMARC, SPF, and DKIM provides a solid foundation.
Implement DMARC with a policy of p=none initially to gather reports and monitor your email flow. This allows you to identify any legitimate emails failing authentication before moving to a stricter p=quarantine or p=reject policy. DMARC reports (RUA and RUF) provide invaluable feedback on how mailbox providers are treating your emails, including authentication failures and perceived spam. You can use a DMARC monitoring service to simplify this process.
Regularly check your infrastructure for any compromises or misconfigurations. This includes your SMTP servers, email service provider (ESP) settings, and any third-party senders. Ensure that all systems sending email on behalf of your domain are authorized in your SPF record and properly configured for DKIM. Mailbox providers like Microsoft and Yahoo are increasingly strict, requiring robust authentication and good sending practices.
Finally, ensure your IP address has a correct reverse DNS (rDNS) mapping. This is a fundamental server configuration that allows an IP address to resolve to a domain name, helping to verify the legitimacy of the sending server. Without a proper rDNS record, your emails are more likely to be flagged as spam. Also, be aware of DNSBLs (DNS-based Blocklists), which are lists of IP addresses known to send spam. Being listed here will severely impede your deliverability.
The path to recovering your email reputation is not always quick, but it is achievable with diligence and adherence to these best practices. Consistency in sending to engaged audiences, maintaining a clean list, and robust authentication are the pillars of long-term deliverability success.
Views from the trenches
Best practices
Implement a strict email list segmentation policy, prioritizing active and engaged subscribers to rebuild trust.
Regularly monitor your domain and IP reputation using tools like Google Postmaster Tools and third-party blocklist checkers.
Ensure all email authentication protocols (SPF, DKIM, DMARC) are correctly configured and aligned for all sending sources.
Maintain consistent sending volumes and gradually increase them as your reputation improves, avoiding sudden large sends.
Use double opt-in for all new subscribers to verify their authenticity and genuine interest in your communications.
Common pitfalls
Continuing to send to unengaged or old contacts, which leads to high bounce rates and spam complaints.
Ignoring early warning signs from reputation monitoring tools, allowing issues to escalate unchecked.
Failing to address underlying technical issues like misconfigured authentication records or compromised accounts.
Attempting to "reset" reputation by abruptly stopping all sends for prolonged periods without a clear strategy.
Neglecting the content quality and relevance of emails, leading to recipients marking them as spam.
Expert tips
For severely damaged reputation, consider a temporary
no-send
period to allow mailbox providers to reset their perception of your domain and IP.
Start your re-warming efforts by sending only to contacts who have engaged with your emails within the last 30-90 days, then slowly expand.
Focus on delivering highly relevant content to a smaller, hyper-engaged audience to generate positive signals before scaling up.
Expert view
Expert from Email Geeks says: Check what Google Postmaster Tools reports for your domain reputation. It's often the first place to see serious issues.
2018-11-28 - Email Geeks
Marketer view
Marketer from Email Geeks says: My domain and IP reputation were bad, with 0.8% spam spikes and 0% SPF success rate, despite my SPF record appearing correct to validation tools.
2018-11-28 - Email Geeks
The path to restored deliverability
Recovering email domain and IP reputation after a spam incident or large accidental send is a marathon, not a sprint. It demands patience, meticulous attention to detail, and a commitment to maintaining a healthy sending ecosystem. The time it takes to recover can vary, but consistent application of these strategies will yield results.
By stopping problematic sending, thoroughly diagnosing the damage, implementing aggressive list hygiene, focusing on engaged audiences, and strengthening your authentication, you can gradually rebuild trust with mailbox providers. This proactive approach not only helps you recover from incidents but also fortifies your email program against future deliverability challenges.
Remember, a good email reputation is your most valuable asset in email marketing. Prioritize it by continuously monitoring your performance and adapting your sending practices to maintain strong deliverability.
Google Postmaster Tools shows a decline.
Yahoo are increasingly strict, requiring robust authentication and good sending practices.
