Abusix Authbl Blocklist
The Abusix Authbl blacklist is a real-time IP blocklist (listing compromised hosts for 12 hours) to stop authentication attacks and brute force attempts.
Updated on 17 Jun 2026: We updated this guide for Abusix AuthBL's current DNSBL zone details, 12-hour listing behavior, and practical cleanup steps before delisting.
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Check if you are listed on Abusix Authbl Blocklist
And 143 other blocklists.
Spamhaus
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Cisco
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abuse.ro
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Calivent Networks
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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.orgTechTheftWhat is the Abusix AuthBL blocklist?
The Abusix AuthBL blocklist is a real-time IP-based DNS blacklist used on outbound mail systems and other authentication services. It is a production Abusix Guardian Mail zone at <APIKEY>.authbl.mail.abusix.zone, with rsync data in lists/authbl.zone for customers with zone access. AuthBL is a short-lived subset of Abusix's exploit data, limited to hosts observed in the last 12 hours.
That 12-hour listing window matters because many affected addresses are dynamic or shared. When an ISP, VPN, NAT gateway, or DHCP pool reassigns an IP, the shorter duration lowers the chance that a later user inherits the old reputation event.
This particular blocklist (blacklist) helps system administrators prevent account compromises and secure authentication services. It is effective against dictionary attacks, brute-force attempts, and unauthorized logins using phished credentials. The list contains IP addresses from sources including:
- Infected hosts and botnet members, including PCs, servers, routers, and IoT devices.
- Shared IPs used by compromised hosts, including VPN, NAT, proxy, and Tor traffic.
- Rare misconfigured SMTP servers and systems observed logging into services they should not access.
- Hosts attempting to authenticate to Abusix honeypots, including SSH and telnet honeypots.
Technically, the Abusix AuthBL blocklist supports both IPv4 and IPv6 addresses. When an IP address is queried and found on the list, it returns 127.0.0.4. Abusix lists test points including 127.0.0.2, 127.0.0.4, ::FFFF:7F00:2, and ::FFFF:7F00:4 for the zone. System administrators can integrate this blacklist into Postfix to reject authenticated relay from listed hosts, or use it as an access control list for HTTP, IMAP, SMTP, SSH, and similar services.
Who runs the Abusix AuthBL blocklist?
Abusix operates the AuthBL blocklist as part of its Guardian Mail DNSBL data. The company maintains security datasets for ISPs, hosting providers, mailbox providers, and other network operators that use DNSBL lookups or zone-transfer workflows to filter abuse.
For AuthBL, the important point is how the data is generated. Listings are automated and based on observed behavior such as exploit activity, authentication attempts against honeypots, and traffic patterns tied to compromised hosts.
How do I get removed from the Abusix AuthBL blocklist?
The removal process for this blacklist is straightforward. Abusix provides a self-service portal for delisting, but you must first address the issue that caused the listing. For AuthBL, common causes include a compromised account, malware on a device behind the IP, an exposed proxy or VPN endpoint, a botnet infection, weak Wi-Fi security, or a NAT gateway shared by an infected device.
To request removal, follow these steps:
- Visit the Abusix Lookup and Delisting page.
- Enter the IP address that is listed on the blacklist.
- If the IP is listed, review the listing details. Click the button to sign up and create a free account.
- Log in to your account and follow the on-screen instructions to request the delisting.
Delist requests are processed immediately. Abusix rebuilds DNS zone files every minute, but it can take up to five minutes for the listing to disappear everywhere the data is cached or synced.
How should you investigate an AuthBL listing?
Treat an AuthBL listing as evidence that the listed IP, or a device behind it, behaved like a compromised authentication source. Delisting without cleanup often leads to relisting.
- Check mail and application logs for successful SMTP AUTH, IMAP, SSH, web panel, or API logins from the listed IP.
- Reset passwords and revoke active sessions for accounts that authenticated from that IP, then check MFA status and recent forwarding rules.
- Scan devices behind the NAT address for malware, update router and IoT firmware, and remove unknown Wi-Fi clients.
- Review outbound queues and delete queued abusive mail before delisting, because old queued mail can restart the problem.
- If the IP belongs to an ISP, hosting company, or mailbox provider, send the bounce or listing evidence to that provider instead of trying to fix shared infrastructure yourself.
What's the impact of being listed on Abusix AuthBL?
For most senders, the impact of a listing on the Abusix AuthBL blocklist is medium. This blocklist is not a general inbound reputation blacklist. Its purpose is to stop listed IPs from authenticating or relaying through protected services.
If your IP is on this blacklist, email delivery fails when an outbound mail server checks AuthBL before allowing authenticated relay. For services that use AuthBL as an access control list, the same listing blocks or flags logins to web panels, IMAP, SMTP AUTH, SSH, and similar services from that IP.
For a shared IP address, one compromised device behind NAT can affect other users who exit through the same address. That is why cleanup and provider coordination matter before requesting removal.
Other Abusix AuthBL blocklists
Abusix Combined Blocklist
Organization
Abusix
Zone
combined.mail.abusix.zone
Type
IP
Impact
Medium
Delisting
Manual
Abusix Domain Blocklist
Organization
Abusix
Zone
dblack.mail.abusix.zone
Type
Domain or IP
Impact
Medium
Delisting
Manual
Abusix Exploit Blocklist
Organization
Abusix
Zone
exploit.mail.abusix.zone
Type
IP
Impact
Medium
Delisting
Manual
Abusix nod List (Newly Observed Domains)
Organization
Abusix
Zone
nod.mail.abusix.zone
Type
Domain
Impact
Medium
Delisting
Automatic
Abusix noip List (Newly Observed IPs)
Organization
Abusix
Zone
noip.mail.abusix.zone
Type
IP
Impact
Medium
Delisting
Automatic
Abusix Policy Blocklist
Organization
Abusix
Zone
dynamic.mail.abusix.zone
Type
IP
Impact
Medium
Delisting
Manual
Abusix Spam Blocklist
Organization
Abusix
Zone
black.mail.abusix.zone
Type
IP
Impact
Medium
Delisting
Manual
