What is the current status and relevance of the NJABL email blacklist?
Matthew Whittaker
Co-founder & CTO, Suped
Published 24 May 2025
Updated 18 Aug 2025
5 min read
When the topic of the NJABL (Not Just Another Bogus List) email blacklist comes up, it's natural to wonder about its current standing. In the dynamic world of email deliverability, the relevance of various blocklists can change quickly. The most direct answer to its current status is that it is no longer operational.
NJABL was once a widely used DNS-based blacklist (DNSBL) that played a significant role in identifying and blocking spam. However, its shutdown marked a notable shift in the email security landscape. For anyone involved in email sending, understanding the implications of defunct blacklists like NJABL is crucial, as misconfigurations or outdated assumptions can inadvertently create deliverability problems for legitimate mail. To get a foundational understanding of these lists, learn more about what email blacklists are and their importance.
NJABL was a prominent DNSBL that aggregated IP addresses known for sending spam, hosting open relays, or facilitating other forms of abuse. It gained considerable traction among email administrators who used it to filter incoming mail, reducing the volume of unsolicited commercial email reaching their inboxes. For a brief overview of the history of email blacklists, it's helpful to explore a brief history of email blacklists.
The service announced its discontinuation, and by March 1, 2013, the NJABL DNSBL zones were emptied. This effectively rendered the blacklist (or blocklist) obsolete, as it no longer contained active data for filtering. The official website for NJABL is also no longer operational. This closure was a significant event, as many mail servers still had configurations that relied on NJABL, leading to potential issues for those unaware of its shutdown. Wikipedia provides more detail on the closure of NJABL.
Even after its official shutdown, some older server configurations continued to query NJABL, leading to mail delivery delays or failures because the DNS lookups for the defunct blocklist would time out. This highlights a critical point in email deliverability: keeping your mail server configurations updated and routinely reviewing the DNSBLs you use is essential to prevent unintended disruptions to your email flow. Understanding what a DNSBL is and its effects can help here.
The danger of using defunct blocklists
Mail delays: Continued queries to an empty or non-existent DNSBL can result in timeouts, significantly slowing down mail processing and potentially causing legitimate emails to be delayed or even bounce.
False positives: While NJABL's zones are empty, other hobbyist or poorly maintained blacklists can cause false positives, blocking valid emails based on outdated or incorrect data.
Resource waste: Your server's resources (CPU, network) are wasted on querying irrelevant or defunct services, impacting overall performance.
Why NJABL is irrelevant today
As of today, the NJABL email blacklist holds no relevance for email deliverability. Any mail server still configured to query it should be updated immediately to remove this entry. Continuing to reference a defunct blocklist can introduce unnecessary delays in email processing and potentially disrupt legitimate mail flow without providing any actual anti-spam benefit. An article on SpamResource urged users to stop using NJABL years ago.
The broader lesson here is the importance of regularly reviewing the blacklists and blocklists that your email infrastructure relies upon. The email threat landscape is constantly evolving, and so too are the tools and services designed to combat spam. Relying on outdated or inactive blocklists, especially hobbyist ones, can be detrimental to your email program. You can learn more about common issues with hobbyist email blacklists.
Instead of focusing on defunct lists, focus should be directed towards actively maintained and highly reputable blocklists. These are the lists that major Internet Service Providers (ISPs) and email services heavily rely on, and being listed on them can severely impact your deliverability. Identifying which email blacklists are most important to monitor is a critical step.
Modern email deliverability practices
For optimal email deliverability, the focus must shift from defunct blocklists like NJABL to robust email authentication protocols and proactive reputation management. Here's a brief look at how current best practices compare to outdated reliance on inactive blacklists:
Outdated approach
Relying on old, unmaintained blacklists. This can lead to mail delays, false positives, and wasted resources. It also provides a false sense of security without actually stopping current spam threats.
Risk factors
DNS timeouts: Queries to defunct DNSBLs cause server delays.
False security: No protection against active spam.
Modern approach
Focusing on active, reputable blacklists and implementing strong email authentication (SPF, DKIM, DMARC). This provides real-time protection and enhances your sender reputation.
Maintaining a healthy sender reputation involves more than just avoiding blacklists. It includes consistent email sending practices, low complaint rates, proper list hygiene, and robust authentication. This holistic approach ensures that your emails consistently reach the inbox.
To keep your email program effective and compliant, focus on major, active blacklists. These are the ones truly impacting deliverability in 2024 and beyond. Regularly checking and acting upon listings on such blacklists will yield much better results than troubleshooting issues related to obsolete lists. Learn more about how email blacklists actually work for a deeper dive.
Views from the trenches
Best practices
Always ensure your mail server configurations are up to date and remove any references to defunct or unmaintained DNSBLs, as they can introduce unnecessary delays.
Prioritize monitoring your IP and domain reputation on widely recognized and actively maintained blacklists (blocklists) that are frequently used by major ISPs.
Implement strong email authentication protocols like SPF, DKIM, and DMARC to build trust with receiving mail servers and prevent spoofing.
Regularly clean your email lists to remove inactive or invalid addresses, reducing bounces and avoiding spam traps that can lead to blacklistings.
Common pitfalls
Overlooking configuration files that still reference inactive blacklists, leading to DNS timeouts and email delivery delays for your outbound messages.
Focusing time and effort on trying to get delisted from irrelevant or defunct blacklists, diverting resources from more impactful deliverability tasks.
Neglecting email authentication standards, which makes your legitimate emails more susceptible to being flagged as spam by modern spam filters.
Failing to monitor deliverability metrics such as bounce rates and complaint rates, which are stronger indicators of sender reputation than inactive blacklists.
Expert tips
Consider setting up automated alerts for major blacklist listings to respond quickly to any issues affecting your sender reputation.
Conduct periodic email deliverability audits to ensure all your sending practices align with current industry standards and ISP requirements.
Engage with postmaster sites for major email providers like Google and Yahoo to understand their specific filtering criteria and improve inbox placement.
Segment your email sends and warm up new IPs gradually to establish a positive sending history and avoid sudden, suspicious spikes in volume.
Marketer view
Marketer from Email Geeks says they believe the NJABL blocklist shuttered many years ago.
2024-01-03 - Email Geeks
Expert view
Expert from Email Geeks says the NJABL website shut down over a decade ago.
2024-01-03 - Email Geeks
The future of email deliverability
In conclusion, the NJABL email blacklist (or blocklist) is definitively defunct. It ceased operations over a decade ago, and any lingering references to it in mail server configurations should be removed to avoid unnecessary complications with email delivery. The landscape of email security and deliverability has evolved significantly since NJABL's peak, moving towards a greater emphasis on sender reputation, authentication protocols like SPF, DKIM, and DMARC, and vigilance against active threats.
For current and future email deliverability success, it's vital to direct your attention and resources towards the blacklists that genuinely impact inbox placement today. Proactive monitoring of your sending reputation and adherence to modern email best practices will ensure your messages reliably reach their intended recipients. Discover more about overcoming email deliverability issues and getting your messages to 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
