How do you get your IP range delisted from Spamhaus SBL for snowshoe spam?
Michael Ko
Co-founder & CEO, Suped
Published 31 Aug 2025
Updated 6 Sep 2025
7 min read
Being listed on a major email blocklist (or blacklist), especially the Spamhaus SBL, can severely impact your email deliverability. When an entire IP range is listed due to snowshoe spam, it presents a complex challenge, as it often indicates a broader issue within the network. This situation requires a strategic approach, particularly if you are part of a larger organization where different services share IP space.
I’ve seen this happen where a legitimate email service, despite its best efforts, finds itself in hot water due to the actions of others within the same IP block. Understanding the nuances of Spamhaus listings, especially for snowshoe spam, is crucial for effective resolution. The key is to demonstrate to Spamhaus that the underlying abuse problem has been thoroughly addressed.
It’s not enough to simply claim innocence, particularly when an entire IP range is implicated. Spamhaus (or any blocklist provider) needs concrete evidence that you have identified and terminated the source of the problematic traffic. This often means working closely with your network provider or, if you are the provider, diligently investigating your client base.
Snowshoe spam refers to a technique where spammers distribute low volumes of spam over a large number of IP addresses to evade detection. Spamhaus's SBL (Spamhaus Blocklist) is a critical list of IP addresses that Spamhaus identifies as being involved in these or other malicious activities. When an entire IP range, like a /22 or /24, is listed, it often signifies a systemic issue.
I often find that when an entire range is blocklisted (or blacklisted), it’s because Spamhaus has observed concerning behavior across that entire network space, not just from one or two IPs. Even unused IPs within that range might be listed preemptively because they fall within a block that has a history of snowshoe spam. The crucial first step is to definitively check your listing on the Spamhaus IP and Domain Reputation Checker to understand the specific listing ID and stated reason, such as SBL619148.
Identifying Snowshoe Spam
Snowshoe spam is characterized by sending low volumes of unsolicited mail across a broad spectrum of IP addresses and often multiple domains to avoid traditional spam filtering. This makes it difficult to pinpoint a single source and often leads to wide-ranging IP blocklistings. Look for patterns in sending behavior across your entire allocated IP space.
Identifying the Root Cause and Taking Action
Once you confirm the listing and understand the reason, the immediate priority is to stop the abusive behavior. This means a thorough investigation of all IP addresses within the affected range. Even if your specific service sends only legitimate, solicited emails, other services or clients within the same network space could be the culprits. This is often where larger network operators or ISPs face significant challenges.
If you are an email service provider (ESP) or a company managing an IP range that multiple clients use, your responsibility extends to monitoring and enforcing anti-spam policies across your entire customer base. This might involve:
Auditing client sending practices: Review your clients' contact acquisition methods and email content for compliance with your anti-spam policy and legal requirements.
Identifying and terminating abusers: If a client is found to be engaged in snowshoe spam, their service should be suspended or terminated immediately. This is often a tough decision but necessary for the long-term health of your IP reputation. Take a hard look at your customer base, as suggested in the Slack thread.
Monitoring for spam traps: Receiving emails from spam traps can quickly lead to a blocklisting. Ensure your clients are cleaning their lists regularly.
Even if your segment of the IP range is clean, if the broader /22 or /24 is controlled by the same entity (e.g., your parent company or network provider), Spamhaus will expect that entity to take responsibility for the entire block. This means internal escalation is often required to address the issue holistically.
Communicating with Spamhaus for Delisting
Spamhaus is generally quite clear about their delisting requirements. For an SBL listing, they usually require contact from the Internet Service Provider (ISP) or the Abuse/Security representative of the organization responsible for the listed IP address range. They expect a detailed explanation of how the abuse problem has been terminated.
This isn't a simple delist request form. They need to know the exact steps taken to resolve the issue. If you're an individual service within a larger network, Spamhaus may not communicate directly with you, as the listing applies to the entire network space owned by your provider. You'll need to work with your parent company or network administrator.
Your role (as a sub-entity)
Internal investigation: Gather all evidence of legitimate sending practices from your part of the IP range.
Policy enforcement: Demonstrate that your clients adhere to strict anti-spam policies and consent requirements.
Escalate internally: Provide all findings to your parent company or network owner for them to address the broader issue with Spamhaus.
Network owner's role (ISP/parent company)
Comprehensive audit: Perform a network-wide audit to identify all sources of snowshoe spam within the entire blocklisted IP range.
Abuse termination: Actively terminate services for any client or internal entity contributing to the spam.
Direct communication: Contact the Spamhaus SBL Team with a detailed plan of action and evidence of resolution.
When communicating, ensure your email subject line clearly states the Spamhaus listing ID and the IP range, for example, SBL619148 185.192.100.0/22. This helps Spamhaus categorize your request correctly. They will prioritize communications that show a genuine understanding of the problem and a clear commitment to resolving it permanently.
Preventing Future Listings and Maintaining Reputation
After successfully delisting from Spamhaus SBL, the ongoing challenge is to prevent future blocklistings (or blacklistings). This requires continuous vigilance and adherence to best practices in email security and deliverability. Proactive monitoring is key.
Implement DMARC: Deploying DMARC with SPF and DKIM provides robust email authentication and visibility into your email sending ecosystem. This helps prevent unauthorized use of your domain and can alert you to potential abuse.
Use a DMARC monitoring tool: Continuously monitor your DMARC reports. Tools like Suped offer comprehensive DMARC monitoring that helps you visualize authentication failures and potential threats, allowing you to take action before a major blocklisting occurs. Suped provides the most generous free plan available for DMARC reporting.
Regular blocklist checks: Utilize a blocklist checker (or blacklist checker) to keep an eye on your IPs and domains across various lists. Early detection is crucial.
If your IP range is frequently listed, consider the possibility of deeper issues, such as compromised accounts, poor list hygiene, or even network vulnerabilities. Addressing these underlying problems is essential for sustainable email deliverability.
Views from the trenches
Best practices
Actively monitor your entire IP range for any suspicious email sending activity.
Maintain strict anti-spam policies for all clients if you are an ESP, and enforce them rigorously.
Regularly audit client mailing lists for legal acquisition and opt-in consent to avoid spam traps.
Ensure clear lines of communication and authority within your organization for handling abuse reports.
Common pitfalls
Assuming an SBL listing is a false positive without a thorough investigation of the entire IP range.
Failing to address abuse from all services or clients within a broad IP block, leading to relisting.
Not having a designated team or individual with the authority to resolve network-wide spam issues.
Underestimating the severity of snowshoe spam listings and the effort required for delisting.
Expert tips
For large IP range listings, Spamhaus expects the network owner, not just a sub-entity, to resolve the issue comprehensively.
Preemptive listings often occur when Spamhaus identifies a broader pattern of abuse within an entire network space.
An external consultant might be beneficial for large, complex cases where internal teams struggle to get traction.
It's crucial to document and explain exactly how the abuse problem has been terminated, not just that it has.
Expert view
Expert from Email Geeks says that an initial listing of a /24 is often concerning and indicates a broader behavioral issue from that IP space. They suggest that it is unlikely to convince Spamhaus to exempt a single /24 range if the entire /22 is showing signs of snowshoe spam. The issue is usually seen as a problem of the whole network not stopping spam.
2024-08-27 - Email Geeks
Expert view
Expert from Email Geeks says that Spamhaus expects an email from the abuse/security staff of the responsible entity (e.g., vercom.pl) with a specific subject line including the SBL ID and IP range, along with a clear explanation of how the abuse problem has been terminated. Until this happens, delisting is very unlikely.
2024-08-27 - Email Geeks
Final thoughts on delisting from Spamhaus
Getting an IP range delisted from Spamhaus SBL for snowshoe spam is a multi-faceted process that goes beyond a simple request. It demands a deep understanding of why the listing occurred, a comprehensive internal investigation to identify and halt all sources of abuse, and clear, transparent communication with Spamhaus demonstrating complete resolution.
For organizations managing extensive IP ranges, this often necessitates internal escalation to ensure the entire network space complies with anti-spam policies. Ongoing monitoring with tools like Suped’s DMARC monitoring and blocklist tools is essential to maintain a healthy sender reputation and prevent future disruptions. By taking these steps, you can navigate the complexities of blocklist removal and safeguard your email deliverability.
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
