0Spam Block List (BL)
The 0Spam blocklist or blacklist protects over one million servers from spam using machine learning. Suped simplifies monitoring your email authentication.
Updated on 17 Jun 2026: We refreshed this guide with 0Spam zone behavior, NBL cautions, and practical cleanup steps.
Summarize with
Check if you are listed on 0Spam Block List (BL)
And 143 other blocklists.
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
TechTheftSpamhaus0SpamCiscoNoSolicitadoURIBLabuse.roALPHANETAnonmailsAscamsBLOCKEDSERVERSCalivent NetworksEFnetJustSpamKempt.netNordSpamRV-SOFT TechnologyScientific SpamSpamikazeSpamRATSSPFBLSuomispamSystem 5 HostingTeam CymruValiditywww.blocklist.de Fail2Ban-Reporting ServiceZapBL2stepback.dkFayntic ServicesORB UKtechnoirc.orgTechTheftSpamhaus0SpamCiscoNoSolicitadoURIBLabuse.roALPHANETAnonmailsAscamsBLOCKEDSERVERSCalivent NetworksEFnetJustSpamKempt.netNordSpamRV-SOFT TechnologyScientific SpamSpamikazeSpamRATSSPFBLSuomispamSystem 5 HostingTeam CymruValiditywww.blocklist.de Fail2Ban-Reporting ServiceZapBL2stepback.dkFayntic ServicesORB UKtechnoirc.orgTechTheftSpamhaus0SpamCiscoNoSolicitadoURIBLabuse.roALPHANETAnonmailsAscamsBLOCKEDSERVERSCalivent NetworksEFnetJustSpamKempt.netNordSpamRV-SOFT TechnologyScientific SpamSpamikazeSpamRATSSPFBLSuomispamSystem 5 HostingTeam CymruValiditywww.blocklist.de Fail2Ban-Reporting ServiceZapBL2stepback.dkFayntic ServicesORB UKtechnoirc.orgTechTheftSpamhaus0SpamCiscoNoSolicitadoURIBLabuse.roALPHANETAnonmailsAscamsBLOCKEDSERVERSCalivent NetworksEFnetJustSpamKempt.netNordSpamRV-SOFT TechnologyScientific SpamSpamikazeSpamRATSSPFBLSuomispamSystem 5 HostingTeam CymruValiditywww.blocklist.de Fail2Ban-Reporting ServiceZapBL2stepback.dkFayntic ServicesORB UKtechnoirc.orgTechTheftThe 0Spam Block List (BL) is an IP-based DNSBL and real-time blacklist (blocklist) used by over one million servers worldwide to filter incoming email. Its primary zone is bl.0spam.org, which is the main database used by the 0spam project to identify sources of spam. If your IP address is listed on this DNSBL, receiving mail servers that use 0Spam can reject your messages or filter them more aggressively. This blocklist was previously known as the FusionZero DNSBL, and some older system configurations still reference the old name.
Who runs 0Spam Block List (BL)?
The blacklist is operated by The 0spam Project, a donation-supported anti-spam project active since 2000. The project uses machine learning and an anti-spam framework to identify spam sources across its public DNSBL, RBL, URLBL, and whitelist zones. Donations and paid network management services help fund platform improvements and support.
- Network administrators can receive notifications when an IP they manage gets listed, including a 24-hour grace period before public listing for confirmed administrators.
- 0Spam sends abuse notifications to official Regional Internet Registry abuse contacts for IP addresses found sending spam.
- IP owners that manage large address blocks can use network asset management tools for bulk removals and abuse notifications.
- Administrators can open research requests when they need help tracing the source of a spam incident.
Which 0Spam zones matter?
0Spam runs several related DNS zones, and they do not all behave the same way. This matters when you are checking a blacklist (or blocklist) result, configuring mail filtering, or working out whether manual delisting is available.
- bl.0spam.org is the main DNSBL and primary IP blacklist for sources of spam.
- rbl.0spam.org is the real-time blacklist. It is fully automated, manual removal is not available, and listings are removed automatically within 24 hours after spam is no longer detected from the IP.
- nbl.0spam.org is the network blacklist for full Class C style network listings with repeated spam trap hits. Use caution with NBL results, and do not use this list as the only reason to block mail.
- dbl.0spam.org is the domain blacklist or URLBL for IPs of domains found in spam messages. It should not be used as the only spam signal.
- wl.0spam.org and dwl.0spam.org are whitelist zones for compliant Network Asset Management members.
How to get removed from 0Spam Block List (BL)
To request removal from the 0Spam blacklist, first check the listed IP and stop the spam source. For bl.0spam.org removals, you must create an account or log in on the 0Spam platform. The delisting process is free, but it is limited to one IP address removal every three hours to prevent automated abuse.
- Scan affected computers and servers for malware, compromised scripts, and unauthorized mail-sending processes.
- Verify that the server is not an open relay and that compromised user accounts have been secured.
- For newsletters or bulk mail, confirm that subscribers use verified double opt-in and that purchased lists are not being used.
- Review DNS records and email authentication so legitimate sending sources are clear before you submit the removal explanation.
- If the IP is only listed in nbl.0spam.org, contact the IP provider or network owner. Manual removal of an NBL listing is not available, and all offending IPs in the block must be fixed.
In rare cases of repeated abuse, an IP address or network block can receive a long-term listing. This usually affects providers that repeatedly fail to stop spam from their networks. To be removed from a long-term listing, stop all sources of spam from the network for at least 60 days before applying for manual removal. 0Spam recommends double opt-in mailing lists and CAN-SPAM compliance to avoid repeat listings.
What's the impact of being listed on 0Spam Block List (BL)?
The impact of being on the 0Spam Block List (BL) is usually medium, but the real delivery effect depends on which recipient systems use the blacklist and how heavily they weight it. Mail servers using this blocklist can reject emails during SMTP delivery, add extra spam scoring, or send messages to the spam folder. A listing is most disruptive when the affected IP handles transactional mail, customer support mail, or bulk campaigns.
During cleanup, Suped's product can help you review DMARC aggregate reports against known sending sources, so unauthorized traffic and legitimate mail flows are easier to separate before you request delisting.
Other 0Spam blocklists
0Spam Network Block List (NBL)
Organization
0Spam
Zone
nbl.0spam.org
Type
IP
Impact
Medium
Delisting
Manual
0Spam Realtime Block List (RBL)
Organization
0Spam
Zone
rbl.0spam.org
Type
IP
Impact
Medium
Delisting
Automatic
0Spam Uniform Resource Locator Block List (URLBL)
Organization
0Spam
Zone
dbl.0spam.org
Type
IP
Impact
Medium
Delisting
Manual
