How to rebuild domain reputation after a spam attack with limited email marketing?
Michael Ko
Co-founder & CEO, Suped
Published 21 May 2025
Updated 19 Aug 2025
7 min read
Dealing with a damaged domain reputation is challenging, especially when a spam attack has occurred and you have limited email marketing activities to rely on for recovery. When a web server is compromised and used to send massive amounts of spam, it severely impacts your domain's standing with mailbox providers like Gmail, Google, and others. This can lead to your legitimate operational emails, such as password resets or notifications, landing in spam folders or being rejected outright.
The typical advice for reputation recovery often centers on gradually increasing email volume to engaged subscribers, but this isn't feasible when email marketing is not a primary activity. Instead, a different strategy is needed, one that focuses on leveraging existing legitimate email traffic, technical configurations, and direct engagement with mailbox providers to repair the damage and restore trust in your domain.
Immediate actions after a spam incident
The first critical step is to halt the unauthorized sending and secure your systems. Immediately after discovering a spam attack, identify the source of the compromise and patch any vulnerabilities. This might involve isolating the affected server or application, changing compromised credentials, and performing a thorough security audit. Failure to do so means any recovery efforts will be futile, as the unauthorized sending could resume, further damaging your reputation.
Next, you need to understand the extent of the damage. Check if your domain or associated IP addresses have been added to any major public or private blocklists (blacklists). Being listed on a blocklist (or blacklist) will severely impede your email delivery. Some blocklists are public and easy to check, while others are internal to mailbox providers. Your email deliverability might have dropped for reasons other than a blocklist entry. For example, your emails might fail due to content, formatting, or sending practices, even without a blacklist entry.
If you find your domain or IP on a blocklist, begin the delisting process. This usually involves submitting a request to the blocklist operator, explaining the situation (e.g., a hacked server) and outlining the steps taken to prevent recurrence. Be prepared to provide evidence of your remedial actions. For Google, you can submit a delisting request directly, explaining the incident. While they may not provide direct feedback, reputation can sometimes be reset within 24 hours if the explanation is clear and convincing.
Reinforce your email authentication
Robust email authentication is foundational for any sender, especially when recovering from a reputation hit. Ensure your domain has proper SPF, DKIM, and DMARC records configured. These protocols prove to mailbox providers that emails originating from your domain are legitimate and authorized. Without them, even clean emails might be viewed with suspicion. Mailbox providers use these records to verify the sender's identity, which significantly influences domain reputation.
SPF (Sender Policy Framework) specifies which mail servers are authorized to send emails on behalf of your domain. DKIM (DomainKeys Identified Mail) adds a digital signature to your emails, allowing recipients to verify that the email was not tampered with during transit. DMARC (Domain-based Message Authentication, Reporting, and Conformance) builds on SPF and DKIM, telling receiving servers what to do with emails that fail authentication and providing valuable feedback reports. Implementing a DMARC policy of p=quarantine or p=reject will prevent future unauthorized use of your domain and prevent spoofing.
Configuring DMARC
Here's an example of a DMARC record that you might use to start monitoring your domain's email activity and gather reports without affecting delivery:
This policy sets your DMARC to p=none, meaning no action will be taken on failing emails, but you'll receive aggregate (RUA) and forensic (RUF) reports to analyze email flows and identify any unauthorized sending.
Closely monitor your domain reputation metrics using tools like Google Postmaster Tools, which provides insights into your domain's performance with Gmail recipients, including spam rates, IP reputation, and DMARC results. For other mailbox providers, you may need to monitor bounce rates and spam complaints from your email service provider's reports.
Leveraging operational email for recovery
Since traditional email marketing volume is limited, you must maximize the positive impact of your operational emails. These are often transactional messages, like order confirmations, shipping updates, or account notifications. These emails typically have high engagement rates because recipients expect and need them. Focus on ensuring these emails are perfectly delivered and positively interacted with.
Encourage recipients of your legitimate operational emails to mark them as Not Spam or Not Junk if they land in the spam folder. Also, encourage them to add your sending address or domain to their address book or contacts. These actions send strong positive signals to mailbox providers that your emails are wanted and legitimate, helping to offset the negative signals from the spam attack. While you cannot explicitly ask every user to do this, consider adding subtle instructions where appropriate, such as in a footer on your website.
The challenge
Limited volume: No large marketing campaigns to generate positive engagement quickly.
Spam classification: Legitimate operational emails are landing in spam, hindering user trust and engagement.
Passive recovery: Relying solely on time without proactive measures is inefficient and slow.
Strategic solutions
Optimize operational emails: Ensure content is clear, concise, and expected, maximizing positive recipient interactions.
User engagement campaigns: Prompt users via other channels (website, app) to check spam and mark as not spam.
Direct communication with ISPs: Submit delisting requests and provide explanations for the incident.
Carefully consider your email sending infrastructure. If the spam attack originated from a shared hosting environment or an IP address with a poor reputation, you might need to migrate to a new dedicated IP or a reputable email service provider. This can help isolate your sending from past negative associations and provide a fresh start for your IP reputation.
Sustaining a healthy domain reputation
Even with limited email marketing, consistent and clean sending practices are paramount for long-term reputation rebuilding. Ensure all your email lists (even for operational emails) are regularly cleaned to remove inactive or invalid addresses. High bounce rates can negatively impact your sender reputation, so maintaining a healthy list is crucial.
Pay close attention to email content. Even transactional emails can trigger spam filters if they contain suspicious links, unusual formatting, or language commonly associated with spam. Ensure your emails are clear, legitimate, and provide expected value to the recipient. Always include an easy-to-find unsubscribe option, even if it's for operational communications, to give recipients control and reduce the likelihood of spam complaints.
Rebuilding domain reputation after a spam attack is not an overnight process; it requires patience and persistent effort. While you might not have the volume of a typical marketing operation, every positive email interaction and every correctly configured technical setting contributes to slowly but surely restoring your domain's trustworthiness with mailbox providers. Regularly review your email logs and deliverability reports for any signs of improvement or new issues.
Views from the trenches
Best practices
Actively encourage users to mark your legitimate emails as 'not spam' or add you to contacts.
Submit delisting requests to Google and other ISPs, explaining the hack incident.
Implement DMARC with a 'p=none' policy initially to gain visibility into email flow.
Maintain clean lists for transactional emails, even without marketing volume.
Ensure all email authentication (SPF, DKIM, DMARC) is correctly configured and monitored.
Common pitfalls
Assuming reputation will fix itself over time without proactive intervention.
Neglecting to secure the source of the spam attack, leading to repeat incidents.
Not monitoring deliverability metrics via Google Postmaster Tools or other analytics.
Sending emails with poor content or formatting, even for operational messages.
Ignoring positive engagement signals from legitimate email recipients.
Expert tips
Consider temporarily disabling authentication (like DMARC) if your IP reputation is strong but domain reputation is poor, to isolate the issue. This is a temporary measure and risky.
Reaching out to Google directly via their delisting contact form can sometimes reset reputation within 24 hours.
Focus on optimizing transactional emails, as they inherently have higher engagement rates.
Leverage other communication channels to guide users on how to positively interact with your emails.
Be patient; rebuilding trust takes time, especially after a significant reputation drop.
Marketer view
Marketer from Email Geeks says encouraging recipients to mark emails as 'Not Junk' and add the sender to their address book can help recover domain reputation.
2019-10-15 - Email Geeks
Expert view
Expert from Email Geeks says if DMARC is not already in use, temporarily disabling authentication might help remove the domain reputation signal from messages, allowing good IP reputation and content to reach the inbox. This is a short-term approach and comes with risks.
2019-10-15 - Email Geeks
Path to recovery
Rebuilding domain reputation after a spam attack, especially with limited email marketing volume, demands a strategic and multi-faceted approach. It starts with immediate action to stop the unauthorized sending and secure your systems, followed by diligent technical configurations and proactive engagement with mailbox providers.
By focusing on strong email authentication, leveraging the positive signals from your operational emails, and maintaining consistent best practices, you can gradually restore trust in your domain. While there's no instant fix for a reputation hit, particularly one caused by a security incident, persistent efforts will eventually yield positive results, ensuring your legitimate communications reach their intended recipients.
