60 Email Blacklists — With Delisting Guides

Spamhaus Zen

zen.spamhaus.org

The most widely used email blacklist in the world. Spamhaus Zen combines SBL, XBL, and PBL into a single lookup zone used by the vast majority of enterprise mail servers globally.

SpamCop Blocking List

bl.spamcop.net

SpamCop is one of the oldest and most widely deployed spam reporting services. The SCBL (SpamCop Blocking List) is automatically generated from user spam reports and typically expires within 24 hours of the last spam report.

Barracuda Reputation Block List

b.barracudacentral.org

The Barracuda Reputation Block List (BRBL) is a free DNSBL used by Barracuda Networks email security appliances worldwide. A listing here can block delivery to many enterprise and SMB customers using Barracuda gateways.

Composite Blocking List (CBL)

cbl.abuseat.org

The CBL (now part of the Spamhaus XBL) lists IPs that have exhibited characteristics of spam-sending malware or are known open proxies and open relays. It is one of the most technically rigorous blocklists, focusing on automated spam sources.

Spamhaus SBL

sbl.spamhaus.org

The Spamhaus Block List (SBL) lists IP addresses belonging to verified spam sources, including known spammers, spam operations, and spam support services. It is one of the most authoritative spam blocklists in existence.

Spamhaus XBL

xbl.spamhaus.org

The Spamhaus Exploits Block List (XBL) lists IPs of computers that have been compromised by spam-sending malware, operated as open proxies, or are otherwise hijacked for spam delivery.

Spamhaus SBL+XBL

sbl-xbl.spamhaus.org

A combined zone that includes both the SBL (Spamhaus Block List for spam sources) and XBL (Exploits Block List for compromised IPs). Commonly used when sites want to query both lists in a single DNS lookup.

SURBL Multi

multi.surbl.org

SURBL (Spam URI Realtime Blocklists) lists domains that appear in spam email bodies as URLs. The multi zone combines data from all SURBL sub-zones. A domain listing here means it has been used in spam campaigns.

Barracuda B2

bb.barracudacentral.org

Barracuda's secondary reputation block list for IPs with poor sending history.

UCEPROTECT Level 1

dnsbl-1.uceprotect.net

UCEPROTECT Level 1 lists individual IP addresses that have directly sent spam as detected by their spam trap network. It is the most targeted of the three UCEPROTECT levels, focusing on single offending IPs.

SpamRATS No PTR

noptr.spamrats.com

SpamRATS No PTR lists IP addresses that lack a valid reverse DNS (PTR) record. A missing PTR record is a red flag for legitimate mail servers and causes delivery failures with many mail systems.

SpamRATS Spam

spam.spamrats.com

SpamRATS Spam lists IPs that have been confirmed as sending spam through SpamRATS's spam trap network. This is the most severe SpamRATS listing, indicating active spam sending.

DroneBL

dnsbl.dronebl.org

DroneBL focuses on listing compromised machines, bots, and drones — systems that have been taken over and are being used to send spam or conduct other malicious activities. It is widely used by IRC networks and mail administrators.

GBUdb Truncate

truncate.gbudb.net

GBUdb (Good, Bad, Ugly database) is an IP reputation database used by many spam filtering systems. The Truncate zone lists IPs with the worst reputation scores — those that are consistently associated with spam.

Backscatterer

ips.backscatterer.org

Backscatterer lists mail servers that generate backscatter — non-delivery reports, auto-replies, or bounce messages sent to forged sender addresses in spam emails. This is considered a mail server misconfiguration.

Spamhaus PBL

pbl.spamhaus.org

The Spamhaus Policy Block List (PBL) lists IP ranges that ISPs and data centers have designated as not authorized to send email directly. It is not a blacklist of spam senders per se, but a policy-based list of IPs that should not send outbound SMTP.

Blocklist.de

bl.blocklist.de

Blocklist.de is a German-operated service that collects attack, brute force, and spam data from fail2ban and other intrusion detection systems running on volunteer servers worldwide. It lists IPs that attack or abuse servers.

Blocklist.de All

all.bl.blocklist.de

The 'all' zone of Blocklist.de aggregates all report categories including SSH attacks, SMTP attacks, web attacks, and spam into a single lookup zone.

Mailspike BL

bl.mailspike.net

Mailspike's primary blocklist zone containing IPs actively identified as spam sources through their global network of participating mail servers.

NoSolicitado Worst Offenders

bl.worst.nosolicitado.org

NoSolicitado's 'worst' zone contains the most severe spam offenders — IPs with very high spam scores or persistent repeat offenders in the NoSolicitado network.

UCEPROTECT Level 2

dnsbl-2.uceprotect.net

UCEPROTECT Level 2 lists entire /24 subnet blocks when too many IPs within the subnet have been individually listed on Level 1. A listing here affects all IPs sharing your network block, regardless of individual behavior.

Passive Spam Block List (PSBL)

psbl.surriel.com

The Passive Spam Block List is a permissive spam blocklist that is easy to get off of. It accepts spam reports from users and automatically expires listings. Designed to have few false positives.

S5H.net Block List

all.s5h.net

S5H.net is a blocklist focused on persistent spam sources and known bad actors. It is maintained with a focus on reducing false positives while catching high-volume spammers.

SpamRATS Auth

auth.spamrats.com

SpamRATS Auth lists IPs that are suspected of being used for credential stuffing or account takeover attacks against mail systems, or that send email without proper authentication.

InterServer RBL

rbl.interserver.net

InterServer's RBL is maintained by web hosting provider InterServer and lists IPs observed sending spam to their mail infrastructure. It is used by their hosting customers and other mail providers.

Mailspike Block List

bl.mailspike.org

Mailspike provides IP reputation services for email. The bl.mailspike.org zone lists IPs with a poor reputation score based on their sending history and spam trap hits across the Mailspike network.

Spam Eating Monkey Block List

bl.spameatingmonkey.net

Spam Eating Monkey maintains a family of blocklists based on spam trap data. The bl zone lists IPs that have sent spam to their network of spam traps.

0spam RBL

rbl.0spam.org

0spam.org operates a family of blocklists aimed at catching spam at various levels. The rbl zone is their primary IP-based blocklist for spam sources detected through their monitoring network.

ZapBL DNSBL

dnsbl.zapbl.net

ZapBL is a DNSBL that lists IP addresses involved in sending unsolicited email. It is used by various mail filtering systems to identify and block spam sources.

Spam-RBL.fr

all.spam-rbl.fr

Spam-RBL.fr is a French-operated blocklist that aggregates spam reports and spam trap data to list IP addresses sending unwanted email, with a focus on European spam sources.

MailCleaner IP RBL

iprbl.mailcleaner.net

MailCleaner is a Swiss-based email filtering solution. Their IP RBL lists addresses observed sending spam to MailCleaner-protected mail systems, which include many European businesses and organizations.

SWINOG DNSRBL

dnsrbl.swinog.ch

SWINOG's DNSRBL is maintained by the Swiss Network Operators Group and lists IP addresses identified as spam sources through their collaborative network monitoring.

Kempt DNSBL

dnsbl.kempt.net

Kempt.net's DNSBL is a spam-focused blocklist maintained through spam trap data and abuse reports. It is used by various mail administrators to filter spam.

Junk Email Filter

black.junkemailfilter.com

JunkEmailFilter.com maintains a blocklist of IP addresses that send unsolicited email. It is used by mail administrators looking for an additional spam filtering layer.

SPFBL DNSBL

dnsbl.spfbl.net

SPFBL.net operates a blocklist focused on IPs that fail SPF checks or send email from domains without proper SPF records, in addition to traditional spam detection.

Mailspike Z (Zero Reputation)

z.mailspike.net

Mailspike's Z zone lists IPs with effectively zero reputation — new, untested IPs with no sending history that should be treated with increased scrutiny by receiving mail servers.

Mailspike Reputation

rep.mailspike.net

Mailspike's reputation zone provides a continuous reputation score for IPs, with poor-reputation IPs effectively being blocked by mail systems using this zone.

Spam Eating Monkey Backscatter

backscatter.spameatingmonkey.net

Spam Eating Monkey's backscatter zone specifically lists mail servers that generate backscatter — bounce messages and delivery failure notifications sent to forged sender addresses in spam.

Abuse.ro RBL

rbl.abuse.ro

Abuse.ro is a Romanian anti-spam project that maintains a blocklist of IPs sending spam to Romanian mail infrastructure and spam trap networks.

RV-Soft DNSBL

dnsbl.rv-soft.info

RV-Soft's DNSBL is a spam-focused blocklist maintained through automated spam detection and manual review of reported abuse.

TTK PTE Singular DNSBL

singular.ttk.pte.hu

The singular.ttk.pte.hu DNSBL is operated by the University of Pécs in Hungary. It lists IPs that have sent spam to the university's mail infrastructure.

Fabel Spam Sources

spamsources.fabel.dk

Fabel.dk maintains a spam source blocklist based on spam activity reported to and detected by their Danish mail infrastructure.

NordSpam Block List

bl.nordspam.com

NordSpam provides email filtering services and maintains a blocklist of spam-sending IPs based on data from their Nordic customer base and spam trap network.

Scientific Spam Block List

bl.scientificspam.net

ScientificSpam.net applies statistical and machine learning techniques to identify spam sources, maintaining a blocklist based on scientifically-validated spam detection methods.

SuomiSpam Block List

bl.suomispam.net

SuomiSpam (Finnish for 'Finland Spam') is a Finnish anti-spam project that maintains a blocklist of spam sources, with a focus on spam affecting Finnish mail infrastructure.

0spam BL

bl.0spam.org

0spam.org's primary blocklist zone for IP addresses identified as spam senders through their comprehensive spam detection infrastructure.

0spam NBL (New/Unknown)

nbl.0spam.org

0spam.org's NBL zone lists newly seen or unknown IP addresses that have not established a positive sending reputation. It helps identify potential spam from new sources.

0spam URL List

url.0spam.org

0spam.org's URL zone lists domains found in spam email bodies. If your domain is listed here, it has been embedded as a URL in spam emails.

0spam DBL (Domain)

dbl.0spam.org

0spam.org's domain blocklist zone, listing domains identified as spam sources or domains used in spam email sending infrastructure.

Schulte RBL

rbl.schulte.org

Schulte.org's RBL is a personal/community blocklist maintained based on spam observations and community reports. It is used by various mail administrators as a supplementary filter.

NSZones SBL

sbl.nszones.com

NSZones operates a spam blocklist as part of their DNS services offering. The SBL zone lists IP addresses identified as spam senders through their monitoring.

IPRange RBL

rbl.iprange.net

IPRange.net operates a DNSBL that lists IP ranges known for spam activity, with a focus on network-level blocking of persistent spam sources.

SpamLookup BSB

bsb.spamlookup.net

SpamLookup.net's BSB (Block Spam Block) zone lists IPs identified as active spam senders through their distributed spam detection infrastructure.

DNSBLChile

dnsblchile.org

DNSBLChile is a Chilean anti-spam project that maintains a blocklist of spam sources targeting Latin American email infrastructure, particularly Chilean ISPs and businesses.

NoSolicitado Blocklist

bl.nosolicitado.org

NoSolicitado (Spanish for 'unsolicited') is a Spanish-language anti-spam project maintaining a blocklist of spam sources with a focus on Spanish-speaking regions.

ZenRBL Poland (IPv4)

ip4.bl.zenrbl.pl

ZenRBL.pl is a Polish anti-spam project that lists IPv4 addresses involved in spam activity, with a focus on protecting Polish and Eastern European mail infrastructure.

VirusFree.cz BIP

bip.virusfree.cz

VirusFree.cz is a Czech Republic-based email security project. The BIP zone lists IPs identified as sources of spam or malware, focusing on threats to Czech and Central European mail infrastructure.

VirusFree.cz Bad

bad.virusfree.cz

VirusFree.cz's 'bad' zone lists IPs with consistent bad behavior patterns — persistent spam senders or sources of malicious email in the VirusFree.cz network.

Brukalai.lt Light List

light.dnsbl.brukalai.lt

Brukalai.lt's 'light' zone lists IPs with lighter spam activity — lower volume spam senders or IPs with suspicious but not definitively spammy behavior.

AnonMails Spam DNSBL

spam.dnsbl.anonmails.de

German-operated spam block list targeting known spam sources.