Blacklist directory

The 35 DNS blocklists our Blacklist Checker queries. Each has its own page explaining what it targets and how to request removal. IP blocklists are checked against a mail server’s IP; domain/URI lists against the domain itself.

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IP blocklists (29)

Spamhaus ZEN
zen.spamhaus.org
The combined Spamhaus zone (SBL + CSS + XBL + PBL) — the single most widely used IP blocklist.
Spamhaus SBL
sbl.spamhaus.org
Spamhaus Block List — manually verified spam sources and spam operations.
Spamhaus XBL
xbl.spamhaus.org
Exploits Block List — hijacked machines, botnet emitters, and open proxies.
Spamhaus PBL
pbl.spamhaus.org
Policy Block List — ranges that should not send direct-to-MX mail (dynamic/residential).
Barracuda Reputation Block List
b.barracudacentral.org
Barracuda Central IP reputation list, used by Barracuda appliances and many others.
SpamCop Blocking List
bl.spamcop.net
IPs reported by SpamCop users and spam traps for sending spam.
SORBS Aggregate
dnsbl.sorbs.net
Aggregate of all SORBS zones (spam, exploits, open relays/proxies, dynamic).
SORBS Spam
spam.dnsbl.sorbs.net
IPs that have sent mail to SORBS spam traps.
SORBS DUHL
dul.dnsbl.sorbs.net
Dynamic User & Host List — dynamically assigned IP ranges.
UCEPROTECT Level 1
dnsbl-1.uceprotect.net
Single IPs caught sending to UCEPROTECT spam traps.
UCEPROTECT Level 2
dnsbl-2.uceprotect.net
Allocations (ranges) with too many Level 1 listings — escalated by network.
UCEPROTECT Level 3
dnsbl-3.uceprotect.net
Entire ASNs with excessive spam — very aggressive; many mail operators ignore it.
Passive Spam Block List (PSBL)
psbl.surriel.com
IPs seen sending to PSBL spam traps.
Backscatterer
ips.backscatterer.org
IPs that send misdirected bounces / backscatter (auto-replies to forged senders).
Mailspike Blacklist
bl.mailspike.net
Mailspike’s worst-reputation IP block list (part of a 10-level reputation scale).
NiX Spam (manitu)
ix.dnsbl.manitu.net
German trap-based IP list; entries auto-expire quickly.
HostKarma Black
hostkarma.junkemailfilter.com
JunkEmailFilter’s combined reputation list (black = bad; also returns white/yellow).
GBUdb Truncate
truncate.gbudb.net
IPs statistically seen sending only spam (safe to “truncate” the SMTP session).
SpamRats ALL
all.spamrats.com
Combined SpamRats list (RATS-Dyna, RATS-NoPtr and RATS-Spam).
SpamRats RATS-Dyna
dyna.spamrats.com
IPs whose reverse DNS looks dynamically assigned (generic naming).
SpamRats RATS-NoPtr
noptr.spamrats.com
IPs with no reverse DNS (PTR) record at all.
SpamRats RATS-Spam
spam.spamrats.com
IPs detected sending spam to SpamRats systems.
DroneBL
dnsbl.dronebl.org
IPs of drones/bots, open proxies and other abusable hosts.
0SPAM
bl.0spam.org
Trap-based IP blocklist run by 0spam.org.
s5h.net RBL
all.s5h.net
General-purpose IP blocklist maintained by s5h.net.
Spam Eating Monkey — IP
bl.spameatingmonkey.net
SEM’s IP reputation block list.
NordSpam IP
bl.nordspam.com
NordSpam IP blocklist.
ImP Spam (imp.ch)
spamrbl.imp.ch
IPs seen spamming, maintained by Swiss provider imp.ch.
ImP Worm (imp.ch)
wormrbl.imp.ch
IPs infected with worms/malware, maintained by imp.ch.

Domain & URI blocklists (6)

Spamhaus DBL
dbl.spamhaus.org
Domain Block List — domains that appear in spam (as sender or in message bodies).
Spamhaus ZRD
zrd.spamhaus.org
Zero Reputation Domains — brand-new domains, listed briefly until they age.
Spam Eating Monkey — URI
uribl.spameatingmonkey.net
SEM URI list — domains appearing in spam messages.
NordSpam Domain
dbl.nordspam.com
NordSpam domain blocklist.
SURBL Multi
multi.surbl.org
Domains that appear in spam message bodies (phishing, malware, spam sites).
URIBL Multi
multi.uribl.com
Domains found in the body of spam / unsolicited bulk email.