Summary
When an agency's IPs and domain are blocklisted by Spamhaus, a multi-faceted approach is essential. Initial steps include contacting Spamhaus to understand the reasons for the listing and identifying the source of the spam activity. If the domain is blocklisted, it's likely due to multiple senders. A dual strategy is needed: short-term (delisting) and long-term (preventing recurrence). Implementing strict confirmed opt-in (COI) processes, regularly cleaning email lists, and monitoring IP and domain reputation are crucial. Employ tools like Sender Score, ReputationAuthority, Microsoft Postmaster Tools, and Google Postmaster Tools. If using shared IPs, collaborate with the hosting provider. Implement SPF, DKIM, and DMARC for authentication. Set up feedback loops with ISPs. Warm up new IPs and consider dedicated IPs for better control. Spamhaus robots following links necessitates strong bot management for COI processes. Ensure the agency's systems are secure and client accounts are investigated, potentially terminating problematic ones. Proactive monitoring of blocklists is vital. A successful resolution involves not just delisting, but also addressing the underlying issues to prevent future blocklistings.
Key findings
- Contact & Understand: Contact Spamhaus to get details and understand the specific reasons for the blocklisting.
- Multiple Senders: If the domain is blocklisted, it's very likely due to multiple senders contributing to the problem.
- Short & Long Term: Implement a dual strategy: short-term (delisting) and long-term (preventing recurrence).
- COI & List Hygiene: Implement strict confirmed opt-in (COI) processes and regularly clean email lists.
- Monitoring: Monitor IP and domain reputation using various tools.
- Shared IP Issues: For shared IPs, collaborate with the hosting provider to resolve issues.
- Authentication & Feedback: Implement SPF, DKIM, DMARC for authentication and set up feedback loops with ISPs.
- Bot Management: If using link verification for COI, implement strong bot management.
- Internal & Client Check: Ensure the agency's systems are secure and investigate client accounts for issues.
Key considerations
- Proactive Monitoring: Proactively monitor blocklists to catch issues early.
- Warm Up IPs: Warm up new IPs to establish a positive sending reputation.
- Dedicated IPs: Consider using dedicated IPs for better control over sending reputation.
- Address Root Cause: Address the underlying root cause of the blocklisting to prevent future recurrences.
- Terminate Problem Clients: Be prepared to terminate relationships with clients who are the source of the problem.
What email marketers say
14 marketer opinions
If your agency's IPs and domain are blocklisted by Spamhaus, the primary steps involve contacting Spamhaus for details, understanding the reasons for the blocklisting (likely due to spam activity originating from your network), and taking corrective actions to prevent future occurrences. This includes implementing strict confirmed opt-in (COI) processes, regularly cleaning email lists, and monitoring your IP and domain reputation using tools. For agencies managing multiple clients, using separate domains or subdomains for each client can help identify the source of the issue. Shared IP addresses require close monitoring and cooperation with the hosting provider to isolate and address problems. Implementing SPF, DKIM, and DMARC, warming up new IPs, using dedicated IPs, and setting up feedback loops with ISPs are also essential to maintain a positive sender reputation. Furthermore, proactive monitoring of blocklists allows for early detection and resolution of issues before they significantly impact email deliverability.
Key opinions
- Contact Spamhaus: Engage with Spamhaus to understand the specific reasons for the blocklisting and request detailed information, such as From addresses and Subject lines of offending emails.
- Identify the Source: Determine the source of the spam activity, which could be due to compromised accounts, clients sending unsolicited emails, or flaws in the data collection process.
- Implement COI: Implement strict confirmed opt-in (COI) processes to ensure subscribers genuinely want to receive emails and reduce spam complaints.
- Clean Email Lists: Regularly clean email lists by removing inactive or invalid addresses to reduce bounce rates and improve engagement.
- Monitor Reputation: Continuously monitor your IP and domain reputation using tools like Sender Score and ReputationAuthority to identify potential issues early.
- Isolate Clients: Use separate domains or subdomains for each client to facilitate identification of problem clients and prevent issues from affecting the entire agency's reputation.
- Shared IP Issues: With shared IPs, address and resolve the issue with your hosting provider, which may involve isolating offending users or implementing stricter sending policies.
- Authentication: Implement SPF, DKIM, and DMARC to authenticate your emails and prevent spoofing, thus improving sender reputation.
- Feedback Loops: Set up feedback loops with major ISPs to receive reports of spam complaints and promptly address these issues.
Key considerations
- Proactive Monitoring: Proactively monitor blocklists to detect and address issues before they significantly impact email deliverability.
- Warming Up IPs: When using new IP addresses, gradually warm them up by starting with low sending volumes and increasing them over time.
- Dedicated IPs: Consider using dedicated IP addresses to gain more control over your sending reputation and avoid being affected by the actions of other senders on shared IPs.
- Address Bot Activity: If using confirmed opt-in via link verification, implement strong bot management to avoid issues with bots following links.
- Anti-Spam Policy: Implement and enforce an anti-spam policy to ensure clients adhere to best practices and prevent spam activity.
Marketer view
Marketer from Email Geeks suggests the blocklisting means Spamhaus received emails on addresses that never subscribed, indicating a flaw in the data collection process where anyone could add someone else's email to the database.
9 Apr 2023 - Email Geeks
Marketer view
Email marketer from EmailToolTester.com advises to proactively monitor your IP and domain on various blocklists using tools like MultiRBL or MXToolbox. Early detection allows you to address issues before they significantly impact your email deliverability.
6 Dec 2023 - EmailToolTester.com
What the experts say
5 expert opinions
When an agency's IPs and domain are blocklisted by Spamhaus, it's crucial to understand the root cause and implement both short-term and long-term strategies. Often, multiple senders or customers are contributing to the problem, particularly if the click domains are blocked. Addressing the issue requires reviewing Spamhaus's details, identifying the source of spam activity, and taking corrective actions. It's essential to ensure the agency's own systems are not compromised, and to investigate and potentially terminate problematic client accounts to prevent recurrence. A short-term focus on delisting must be paired with a long-term strategy of fixing the underlying problem to avoid being re-listed.
Key opinions
- Multiple Senders: If your domain is blocklisted, the issue likely stems from multiple senders within your network contributing to spam activity.
- Comprehensive Understanding: Thoroughly understand the reasons provided by Spamhaus for the blocklisting, focusing on identifying the source of spam activity.
- Dual Strategy: Implement both short-term (delisting) and long-term (preventing recurrence) strategies to address the blocklisting effectively.
- Internal Security: Ensure the agency's own mail servers are secure and not a source of spam due to hacking or misconfiguration.
- Client Accountability: Investigate client accounts for spam activity and be prepared to terminate relationships with clients who are the source of the problem.
Key considerations
- Delisting Process: Familiarize yourself with the Spamhaus delisting process and follow their guidelines for requesting removal from the blocklist.
- Client Communication: Communicate transparently with clients about the blocklisting issue and the necessary steps to resolve it, ensuring their cooperation.
- Preventative Measures: Implement preventative measures such as stricter email marketing policies, enhanced monitoring, and improved list hygiene to avoid future blocklistings.
- Resource Allocation: Allocate resources to investigate and address the root cause of the blocklisting, as a quick fix without addressing the underlying issues will likely lead to re-listing.
- Long-Term Reputation: Focus on building and maintaining a positive sender reputation by adhering to email marketing best practices and prioritizing deliverability.
Expert view
Expert from Word to the Wise explains that you need to ensure you’re not the source of the problem. If your mail server has been hacked, that could be a source. Once your system is confirmed clear, you need to look into your customers and ensure they aren’t the problem. Be prepared to terminate problem customers.
4 Jun 2025 - Word to the Wise
Expert view
Expert from Email Geeks explains that if the domain is being listed, it very likely means there is more than one sender causing the problem. If click domains are blocked, it's very likely due to spam from multiple customers.
4 Jun 2023 - Email Geeks
What the documentation says
4 technical articles
When Spamhaus blocklists an agency's IPs and domain, the immediate action is to identify the listed IP or domain using the Spamhaus Blocklist Removal Center to understand the reason, typically spam activity from your network. Additionally, it is important to use tools provided by email providers (Microsoft Postmaster Tools and Google Postmaster Tools) to monitor sender reputation, spam complaint rates, and feedback loop complaints. Ensuring proper implementation and configuration of SPF, DKIM, and DMARC records is also crucial for email authentication and improved deliverability.
Key findings
- Identify Listing: Use the Spamhaus Blocklist Removal Center to identify the listed IP address or domain.
- Understand the Reason: The primary reason for blocklisting is usually spam activity originating from the agency's network.
- Monitor Reputation: Use Microsoft Postmaster Tools and Google Postmaster Tools to monitor sender reputation.
- Implement Authentication: Implement SPF, DKIM, and DMARC records for email authentication.
Key considerations
- Remediation: Following identification of the reason for listing on Spamhaus, immediate steps should be taken to remediate the cause.
- Ongoing Monitoring: Consistent monitoring of sender reputation and spam complaint rates is important.
- Proper Configuration: Ensure that SPF, DKIM, and DMARC records are correctly configured to improve deliverability.
- Tool Utilization: Actively use available tools from email providers like Microsoft and Google to track email performance.
Technical article
Documentation from Google.com states that you should use Google Postmaster Tools to monitor your domain's reputation, spam rates, and feedback loop complaints. This data helps identify and address issues affecting your deliverability to Gmail users.
14 Nov 2024 - Google.com
Technical article
Documentation from RFC-Editor.org explains to implement SPF, DKIM, and DMARC records to authenticate your emails and prevent spoofing. Ensure these records are correctly configured to improve your sender reputation and email deliverability.
18 Nov 2023 - RFC-Editor.org
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