What is the Spamhaus EDBL API and how does it work?
Matthew Whittaker
Co-founder & CTO, Suped
Published 14 Apr 2025
Updated 19 Aug 2025
9 min read
Managing email deliverability and ensuring your messages reach the inbox is a constant challenge. A key component of this involves understanding and navigating blocklists (or blacklists), which are crucial for maintaining sender reputation. Among the many tools available, the Spamhaus EDBL API offers a deeper insight into domain reputation than traditional blocklist lookups.
The EDBL, or Enhanced Domain Blocklist, is an extension of Spamhaus’s Domain Blocklist (DBL), providing a more granular view of a domain's reputation. While the DBL traditionally indicates if a domain is listed, the EDBL API goes further by assigning a numerical score and revealing additional data points that contribute to that score. This extra layer of detail can be invaluable for email marketers and system administrators who need to proactively manage their sending infrastructure and ensure compliance.
It’s about moving beyond a simple yes or no listing status to understanding the underlying factors that influence a domain's standing. This allows for more informed decisions, whether you're onboarding a new client, troubleshooting deliverability issues, or simply monitoring your own email program's health. The insights from the EDBL API can help you prevent future listings and maintain a strong sending reputation, which is essential for effective email communication.
The Spamhaus EDBL API provides a comprehensive reputation score for a domain, along with various contributing factors. Unlike a simple lookup that just tells you if a domain is on a blocklist, the API returns a numerical score. A score exceeding 5 typically indicates a listing on the DBL (Domain Blocklist). The lower the score, the better the domain's reputation. For instance, reputable domains often show scores in the negative hundreds, like -142, suggesting a very clean record. The API integrates over 50 different criteria to calculate this score, offering a holistic view of the domain’s health.
This API also provides other valuable information that goes beyond just a score. It can reveal registrar information, whether spam trap hits have been observed, and the IP addresses associated with the domain. While Spamhaus’s DBL primarily lists full domains rather than subdomains, the score derived from the EDBL API is designed to encompass the overall reputation of the entire domain, including all its subdomains. This means that a poor reputation on a subdomain can still impact the primary domain’s score in the EDBL system. For more on this, consider reading how Spamhaus lists subdomains vs. root domains.
Example EDBL API response for a healthy domainjson
status "ok"
score -111
registrar "Tucows Domains Inc."
date_created "1997-12-15"
first_seen "2009-10-04 14:09:14"
last_seen "2019-07-05 19:21:27"
spamtrap_hits "yes"
anon_whois "no"
ip
0
ip "159.65.165.66"
last_seen "2019-07-05 19:22:21"
This detailed output allows for a more nuanced understanding of a domain's standing, moving beyond a simple block or no-block status. It enables users to identify potential issues before they escalate into full blocklist listings, making it a powerful tool for preventative email deliverability management. The API provides a data-driven approach to maintaining a good sending reputation.
Key data points provided by EDBL API
The rich data returned by the Spamhaus EDBL API goes beyond merely indicating a blocklist status. It provides several key data points that are critical for assessing and managing domain reputation. Understanding these elements can help you diagnose problems and implement effective solutions before a domain hits a major blocklist (or blacklist).
The core of the API's utility lies in its comprehensive data. For example, spam trap hits are a significant indicator of poor list hygiene. If a domain shows yes for spamtrap_hits, it signals that the domain has sent mail to a spam trap, which severely damages reputation. This is something you should address immediately by reviewing your list acquisition practices, as explained in our guide on what spam traps are and how they work. Similarly, the anon_whois field can indicate if a domain is using anonymous WHOIS information, which might raise suspicion depending on the context. Legitimate businesses generally prefer transparent WHOIS records.
The API also offers timestamps like date_created, first_seen, and last_seen. These can help you track the domain's historical activity and identify when potential issues arose. Knowing when an IP address was last_seen sending email can also be beneficial for isolating problematic sending behaviors. The combination of these data points provides a strong foundation for understanding your email domain reputation.
Data Point
Description
Significance for Reputation
Score
Numerical value indicating domain reputation (lower is better).
Threshold of 5 or higher means blocklisted.
Registrar
The domain's registrar.
Useful for WHOIS lookups and identifying legitimate ownership.
Spam trap hits
Indicates if the domain has sent email to a spam trap.
A strong negative signal, often leading to immediate listing.
Anon WHOIS
Whether anonymous WHOIS protection is enabled.
Can be a minor flag for some mail servers, depending on their policies.
Associated IPs
IP addresses identified with the domain's sending activity.
Helps trace problematic sending sources connected to the domain.
Benefits of using the EDBL API
The Spamhaus EDBL API provides significant advantages for anyone involved in email operations, from marketers to system administrators. Its granular data allows for proactive reputation management, which is far more effective than reactive troubleshooting after a blocklisting event. By integrating this API into your workflows, you can improve overall email deliverability and avoid common pitfalls associated with poor domain reputation.
One of the primary benefits is its utility during client onboarding. Before allowing a new client to send emails through your platform, you can query their domain to assess its current reputation. This helps you identify potential risks early on and prevent a client's poor standing from negatively impacting your shared sending infrastructure. Similarly, it's invaluable for troubleshooting deliverability issues. If a client reports emails going to spam, the API can quickly tell you if their domain's reputation score is a contributing factor, allowing you to focus your investigation.
Furthermore, the EDBL API is highly useful for filtering both inbound and outbound email. By integrating API queries into your mail server's filtering logic, you can automatically block messages from domains with poor EDBL scores, reducing spam reaching your users. For outbound mail, you can prevent your users from sending emails that could harm your own domain's reputation. This proactive filtering is crucial for maintaining overall network hygiene and ensuring consistent deliverability across your entire sending ecosystem.
Best practices for using the EDBL API
Integrate early: Use the API during client or domain onboarding to check for existing reputation issues.
Monitor regularly: Automate daily or weekly checks for your domains and key client domains.
Establish thresholds: Define what score requires immediate attention versus ongoing monitoring.
Analyze full data: Don't just look at the score, examine spam trap hits, WHOIS, and associated IPs.
Understanding the scoring and listings
Understanding the numerical score provided by the Spamhaus EDBL API is key to interpreting a domain's reputation. As mentioned, a score of 5 or higher indicates that the domain is likely listed on the Spamhaus DBL. Conversely, a lower, often negative score signifies a better reputation. For example, some highly reputable domains may show scores as low as -142, indicating a very clean history and no association with malicious activity.
While the score is a primary indicator, other factors influence it significantly. Spam trap hits, even historical ones, can elevate a domain's score. A domain that has hit a spam trap in the past might exhibit a score closer to zero, or even slightly positive (e.g., -1 or -2), even if it's not currently active in sending spam. This is because spam traps are a strong signal of poor list management or malicious intent, and their impact on reputation can linger.
It’s important to remember that Spamhaus uses over 50 different criteria to determine this score. These criteria are dynamic and constantly updated to reflect evolving spam tactics. While a specific impact of a single spam trap hit from years ago might not be precisely quantified publicly, its presence in the data suggests that it still contributes to the overall risk assessment. For more detailed information, I recommend checking out the official Spamhaus Technology vendor list.
Good reputation
Score: Below 5, often significantly negative (e.g., -100 to -142).
Actively use EDBL API for proactive domain reputation management, not just reactive checks.
Set up automated alerts for significant score changes on monitored domains to act quickly.
Use the 'spamtrap_hits' data point as a critical indicator for list cleaning efforts.
Consult the 'associated IPs' data to identify specific sending sources impacting domain reputation.
Common pitfalls
Overlooking the EDBL API's detailed data, focusing only on a simple 'listed' or 'not listed' status.
Ignoring historical spam trap hits, assuming they no longer affect current domain scores.
Not integrating EDBL checks into client onboarding, leading to inherited reputation issues.
Misinterpreting the numerical score, believing a low positive number is better than a negative one.
Expert tips
Validate EDBL API data against other reputation sources to get a comprehensive view.
Understand that Spamhaus uses over 50 criteria for EDBL scores, making it a robust metric.
Use the API to identify trends in domain behavior over time, not just snapshots.
Consider EDBL's value for both inbound and outbound email filtering to protect your network.
Marketer view
A marketer from Email Geeks says they use the Spamhaus EDBL API to check domain scores during client onboarding and for troubleshooting. The lower the score, the better the domain's reputation.
2019-07-19 - Email Geeks
Marketer view
A marketer from Email Geeks says that domains hitting a spam trap often have higher, less favorable scores (e.g., -1 or -2) compared to those without spam trap hits, which can score much lower (e.g., -96).
2019-07-19 - Email Geeks
Improving email deliverability with advanced insights
The Spamhaus EDBL API represents a significant advancement in understanding and managing domain reputation. Moving beyond simple blocklist checks, it provides a nuanced scoring system and rich data points that empower email professionals to make informed decisions. By offering insights into factors like spam trap hits, registrar information, and associated IP addresses, the EDBL API enables a proactive approach to email deliverability.
Integrating this API can significantly enhance your email strategy, whether you're onboarding new clients, troubleshooting existing issues, or fortifying your defenses against unwanted mail. The ability to monitor and react to reputation changes before they lead to severe deliverability problems is a game-changer. It supports a robust email program, ensuring your legitimate messages consistently reach their intended recipients while minimizing exposure to malicious activity.
Ultimately, leveraging tools like the Spamhaus EDBL API is not just about avoiding blocklists, it's about building and maintaining a trusted sending reputation. In today's complex email landscape, detailed intelligence is your best defense against deliverability challenges and a critical asset for any successful email campaign. By focusing on these granular details, you can significantly improve your chances of inbox placement and ensure the effectiveness of your communications.
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
