Finding a sending IP or domain listed by Spamhaus can disrupt campaigns fast. The right response is calm, structured, and procedural. Most listings are resolvable when teams focus on evidence, recent changes, and clear remediation.
Step 1: Pause and identify the exact listing
Start by confirming which Spamhaus blocklist applies. Each list points to a different class of risk and has its own listing criteria. Understanding the list, helps understand the proper resolution path.
- ZEN Blocklist aggregates several Spamhaus data sources, you’ll need to find the listing in one of the options below. It is widely used and often causes bounces or spam placement.
- Spamhaus Blocklist (SBL) flags confirmed spam sources, often tied to list quality or repeated policy issues.
- Combined Spam Sources (CSS) highlights ongoing poor sending behaviour, such as spam traps or very low engagement.
- Policy Blocklist (PBL) lists IPs not intended to send email directly, including residential or dynamic addresses.
- Exploits Blocklist (XBL) indicates compromised systems, malware, or open proxies.
- Domain Blocklist (DBL) targets domains used in spam or malicious campaigns, including links, images, and tracking domains.
Next, assess the impact. The immediate effects are:
- Opens and clicks decline.
- Spam placement and bounces increase.
Depending on the listing, the path to resolution will be different: some auto-expire when the problem sending stops, but most require intervention and a conversation with the Spamhaus support team.
Step 2: Review the listing details like an audit
Each listing includes context. Treat it as an incident report, not a judgement. Review timestamps, IPs, domains, and behavioural notes carefully.
Different lists require different fixes. Infrastructure problems will not resolve consent gaps. Content changes will not fix compromised servers. Aligning the response to the evidence saves time.
Step 3: Isolate the cause using a decision tree
Most listings follow a recent change. Use this practical flow to narrow the cause.
Did anything change in the last 7–14 days?
If no, review longer-term engagement trends and infrastructure logs.
If yes, continue.
Was new mail or higher volume introduced?
If yes, pause the send and review throttling and targeting.
If no, continue.
Did data sources change?
Purchased lists, aggressive reactivation campaigns, and form compromises are common triggers. Pause immediately and investigate.
Did automation or systems change?
New workflows, integrations, tracking domains, or IPs often correlate with listings. Roll back and reassess.
Complicated workflows can introduce unexpected issues.
Does your system already have a built-in suppression process, have you confirmed that it is working properly, or are there gaps in the workflows that could be introducing bad data?
Stabilising traffic matters more than maintaining volume during investigation.
Step 4: Engage support once fixes are in place
Start by working with your ESP, or your favourite consultants (we are here to help you). After addressing possible root causes, contact Spamhaus support if required. Be polite, honest, and specific. Explain what happened, what was corrected, and how recurrence will be prevented.
If the cause remains unclear, ask for guidance directly. Guessing or offering vague explanations slows resolution.
Handling this communication carefully matters. Spamhaus plays a key role in protecting the email ecosystem and has a direct impact on your deliverability.
If you’re unsure how to proceed, can’t identify the root cause of a listing, or want expert help getting delisted, contact us.
Step 5: Request resolution and continue monitoring
Follow the delisting process for the specific list. Resolution timelines vary. Some clear quickly, others take days. While waiting, monitor bounces, complaints, and engagement closely. The longer you wait to correct an issue, the longer you might need for resolution.
After delisting: strengthen the program
A listing often reveals deeper gaps. Use this moment to improve fundamentals. Consider reconfirmation campaigns, opt-in process updates, and permanent removal of bad data. Review automation logic and sending cadence before returning to normal volume.
Final thoughts
Spamhaus listings are operational incidents, not failures. Teams that respond with structure and transparency recover faster and send safer long term.
Email Industries supports both active blocklist remediation and preventative deliverability programs. Looking to fix today’s issue and avoid the next one? Reach out to schedule a consultation and get expert guidance.
