What steps should I take when my domain is blocked by Spamhaus?
Matthew Whittaker
Co-founder & CTO, Suped
Published 17 May 2025
Updated 15 Aug 2025
8 min read
When your domain is blocked by Spamhaus, it can feel like a sudden, severe blow to your email operations. This type of listing, particularly on the Spamhaus Domain Blocklist (DBL) or Spamhaus Blocklist (SBL), means that emails originating from or linked to your domain are being rejected by a significant portion of the internet. The immediate consequence is a drastic drop in your email deliverability, preventing legitimate messages from reaching their intended recipients.
I know how frustrating it can be to see your important communications bounce back, impacting everything from customer service to sales and marketing efforts. The key to navigating this situation is to act swiftly and systematically to identify the root cause and implement lasting solutions. Without proper action, your domain's reputation will continue to suffer, leading to prolonged email delivery issues.
The first crucial step is to confirm that Spamhaus (or a Spamhaus-powered blocklist) is indeed the reason for your email delivery issues. Bounce messages often provide clues, sometimes directly mentioning Spamhaus or an associated blocklist. You can use the official Spamhaus IP and Domain Reputation Checker to perform a lookup for your domain and any associated sending IP addresses. This tool will tell you which specific Spamhaus blocklist (blacklist) your domain or IP is listed on, such as the DBL (Domain Blocklist) or SBL (Spamhaus Blocklist). For more information on blocklists, see the guide on email blocklists.
Once you confirm a listing, it's vital to understand why your domain was added. Spamhaus DBL listings typically occur due to spam-like content originating from or linked to your domain, compromised websites hosting malware, or abusive email sending practices. The SBL, on the other hand, usually lists IP addresses involved in sending spam, hosting spam support services, or other malicious activities. For a deeper dive into the causes, explore what causes Spamhaus blacklisting.
A critical part of this initial phase involves reviewing your email logs and bounce data. Look for patterns in rejected emails, specific error codes, and any unusual outbound activity. This data can help you pinpoint the exact source of the problematic emails, whether it's a compromised account, a misconfigured script, or an email campaign that triggered spam filters due to poor list hygiene or content.
Check your domain and IP reputation
To determine if your domain or associated IP addresses are listed, visit the Spamhaus IP and Domain Reputation Checker. This tool provides detailed information on any active listings and the specific blocklist your assets are on. This is the official way to check your status directly with Spamhaus.
Bounce message indicating a Spamhaus blockplaintext
550 5.7.1 Service unavailable; Client host [XXX.XXX.XXX.XXX] blocked using sbl.spamhaus.org; See: https://www.spamhaus.org/sbl/
Stopping the problematic activity
Getting off a Spamhaus blocklist (or blacklist) fundamentally requires stopping the behavior that caused the listing in the first place. For domains, this often means addressing issues related to compromised systems, malicious content, or sending unwanted email. If your domain is associated with an email service or marketing platform, you must identify which client or internal process is generating the problematic traffic. Spamhaus notes that DBL listings automatically drop off within 2-3 days if no further spam is detected. However, SBL delisting may require direct intervention from your internet service provider (ISP) or email service provider, who must demonstrate that the underlying issue has been resolved, as highlighted in Spamhaus's general FAQs on delisting.
This can be a challenging conversation, especially if the problematic activity comes from a high-value client or an internal team unwilling to change their practices. However, Spamhaus is clear: the listing will remain until the source of the spamming ceases. In such cases, you might face a difficult decision: continue to suffer deliverability issues affecting all your legitimate email or take decisive action against the source of the spam. It's often necessary to either suspend or terminate accounts engaging in abusive practices, or at the very least, educate them on proper email hygiene and ensure strict compliance with your acceptable use policies.
Implementing stricter email sending policies is crucial. This includes enforcing double opt-in for all new subscribers, regularly cleaning your email lists, and monitoring for unusual activity. For businesses running email marketing campaigns, it is vital to ensure that your clients have explicit permission (opt-in) from their contacts. A common pitfall is purchasing email lists, which inevitably leads to spam trap hits and subsequent blacklisting.
The problem: reluctance to suspend spammers
Fear of losing clients: Management or sales teams may resist suspending clients engaged in spamming due to revenue concerns.
Lack of understanding: Decision-makers might not fully grasp the long-term damage to sender reputation and overall business by ignoring blocklist (blacklist) issues.
Short-term focus: Prioritizing immediate revenue over sustainable email deliverability and brand health.
The solution: prioritizing deliverability
Educate stakeholders: Clearly communicate the impact of Spamhaus listings on all email operations and overall business reputation.
Enforce policies: Implement and strictly enforce acceptable use policies that prohibit spamming and require explicit opt-in.
Demonstrate consequences: Show how blocklistings affect legitimate users and lead to broader financial losses than losing a single problematic client.
Implementing technical and policy solutions
Once the source of the problem is contained, you need to implement technical fixes to prevent future issues. Start by reviewing your domain's email authentication records: SPF, DKIM, and DMARC. Ensure they are correctly configured and aligned, as misconfigurations can inadvertently contribute to a poor sending reputation. A robust DMARC policy, for instance, helps protect your domain from unauthorized use and provides valuable feedback on email authentication failures. You can learn more about these in our guide to DMARC, SPF, and DKIM.
Beyond authentication, focus on list hygiene. Spam traps are a significant signal for blocklists (blacklists), indicating poor list acquisition practices or outdated recipient lists. While you can't identify individual spam traps, reducing hits means consistently cleaning your email lists, removing inactive or invalid addresses, and avoiding purchased lists. This proactive approach significantly improves your email reputation.
Finally, enhance your overall security measures. Spamhaus listings, especially XBL (Exploits Blocklist), often point to compromised systems, open relays, or malware on your network. Ensure all servers and websites associated with your domain are secure, regularly patched, and free of vulnerabilities. This might involve updating software, strengthening passwords, and implementing intrusion detection systems to prevent unauthorized access and abuse.
Issue
Impact
Solution
Compromised accounts/systems
Often leads to SBL/XBL listings due to spam or malware distribution.
Can cause emails to fail authentication and be marked as spam.
Verify and correct your DMARC record, SPF, and DKIM entries. Ensure proper alignment.
Requesting delisting and ongoing monitoring
For DBL listings, Spamhaus often automatically removes a domain within 24-72 hours once the spamming has stopped and no new spam traps are hit. You can monitor your status using their checker tool. For SBL listings, the process typically requires your Internet Service Provider (ISP) or host to submit a delisting request, providing evidence that the issue has been resolved. Spamhaus maintains a delisting procedure for SBL that outlines these steps.
It's important to be patient but persistent. Spamhaus will not delist a domain or IP until they are confident that the underlying cause of the listing has been addressed and will not recur. Simply requesting removal without fixing the problem is futile, as they will quickly re-list your domain if spam activity continues. Their DBL FAQs explicitly state that if your domain is still listed, it means they are still seeing spam, indicating that the problem has not been fully resolved.
To prevent future blocklistings and maintain a healthy email reputation, ongoing monitoring is essential. Regularly use a blocklist checker to keep an eye on your domain and IP addresses. More broadly, invest in robust email deliverability monitoring tools that track your sender reputation, bounce rates, complaint rates, and spam trap hits. This proactive approach allows you to detect and address potential issues before they escalate into serious deliverability problems and another Spamhaus listing.
Maintain a strong sender reputation
Regular list hygiene: Continuously clean your email lists by removing invalid, inactive, or unengaged subscribers.
Monitor engagement: Track open rates, click-through rates, and unsubscribe rates. Low engagement can signal disinterest, increasing spam complaints.
Implement double opt-in: Require subscribers to confirm their subscription, ensuring legitimate and engaged contacts.
Monitor DNS: Regularly check your Google Postmaster Tools and Microsoft SNDS accounts for feedback on your sending reputation.
Security audits: Conduct routine security checks of your servers and systems to prevent compromises that could lead to spamming.
Review DMARC reports: Use DMARC monitoring to gain visibility into your email authentication status and identify potential abuse of your domain.
Views from the trenches
Best practices
Continuously monitor your bounce and complaint rates, looking for any spikes that might indicate underlying issues with your sending practices or list quality. Timely detection is key.
Proactively set up and utilize postmaster tools from major mailbox providers, such as Google and Microsoft, to gain insights into your sender reputation and identify potential problems early.
Ensure you have robust processes in place for managing client lists and verifying opt-in consent to prevent the inclusion of spam traps or unengaged contacts.
Common pitfalls
Believing that identifying specific spam traps will solve the problem; the real issue is poor list hygiene or problematic sending practices that attract traps in the first place.
Reluctance to suspend or remove clients or internal users who are causing the spamming issues, which prolongs the blocklisting.
Expecting immediate delisting from Spamhaus without first addressing and rectifying the root cause of the listing.
Expert tips
If your superiors are resistant to addressing spamming clients, present them with clear data on the financial losses caused by poor deliverability and blacklisting impacting legitimate business.
Focus on improving your overall data sources and identifying the channels that are bringing in bad traffic or leading to poor user engagement, rather than just chasing individual spam traps.
Understand that Spamhaus will not delist you if spam activity persists; their system confirms the problem is still ongoing.
Expert view
Expert from Email Geeks says no tools will expose the specific spam traps, as they are kept secret to remain effective.
August 19, 2020 - Email Geeks
Expert view
Expert from Email Geeks says spam traps are a signal of list issues, and fixing the problem lists will resolve the underlying issue rather than just removing the signal.
August 19, 2020 - Email Geeks
Sustaining a healthy email reputation
Being blocked by Spamhaus is a serious issue that demands immediate and thorough action. The process involves identifying the specific listing, diligently pinpointing and stopping the source of the problematic activity, implementing necessary technical and policy changes, and then submitting a delisting request. Remember, Spamhaus prioritizes the cleanliness of the internet's email ecosystem, and they will only delist your domain or IP once they are confident that the abuse has genuinely ceased.
Ultimately, preventing future blocklistings (blacklistings) is about cultivating a culture of responsible email sending. This means continuous vigilance over your email practices, maintaining clean lists, ensuring strong security, and proactively monitoring your sender reputation. By adhering to best practices and promptly addressing any issues, you can safeguard your email deliverability and ensure your messages consistently reach the inbox.
Spamhaus
0Spam
Cisco
NoSolicitado
URIBL
abuse.ro
ALPHANET
Anonmails
Ascams
BLOCKEDSERVERS
Calivent Networks
EFnet
JustSpam
Kempt.net
NordSpam
RV-SOFT Technology
Scientific Spam
Spamikaze
SpamRATS
SPFBL
Suomispam
System 5 Hosting
Team Cymru
Validity
www.blocklist.de Fail2Ban-Reporting Service
ZapBL
2stepback.dk
Fayntic Services
ORB UK
technoirc.org
TechTheft
Regularly check your Google Postmaster Tools and 
Microsoft SNDS accounts for feedback on your sending reputation.
