Abusix Policy Blocklist
The Abusix policy blocklist (or blacklist) identifies IP addresses that must use smarthosts for relaying instead of connecting to SMTP servers directly.
Updated on 17 Jun 2026: We updated this guide with Abusix-specific listing criteria, delisting behavior, and clearer guidance on when a policy listing needs action.
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Check if you are listed on Abusix Policy Blocklist
And 143 other blocklists.
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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 Policy Blocklist?
The Abusix Policy Blocklist is an IP-based blocklist (or blacklist) for IP addresses that should not connect directly to external SMTP or MX servers. These IPs should send mail through a smarthost, ISP relay, or email provider instead of making direct SMTP connections. The list is queried through the DNS zone dynamic.mail.abusix.zone. Its purpose is to preemptively identify IP addresses that are unsuitable for direct email sending, including newly compromised hosts, hijacked IP space, and consumer or hosting IPs that do not look like dedicated mail servers.
Abusix builds this policy blacklist by scanning IPv4 space and applying a DNS and mail-server policy to each IP address. The policy is mainly focused on reverse DNS (rDNS), but open mail ports and welcome-list status also matter. Key listing and exclusion criteria include:
- The IP address must have a valid rDNS record.
- The rDNS must not be a generic or templated hostname. For example, it should not contain multiple parts of the IP address in decimal, hex, or another encoded form.
- The rDNS should reflect the hostname of the SMTP server, with practical exceptions for names that clearly indicate static, mail, mx, or smtp use.
- Contiguous ranges of IP addresses must not all share the same rDNS record.
- IPs with port 25, 465, or 587 open are excluded from this policy list.
- IPs on Abusix welcome-list data are excluded.
When an IP is queried against this blocklist, return codes indicate the reason for the listing. A return code of 127.0.0.11 means the host has generic rDNS, while 127.0.0.12 means the host has no rDNS. It is normal for non-SMTP server IPs to appear on this list, and that should not affect web hosting, VPN access, DNS hosting, or other non-email services.
Who runs the Abusix Policy Blocklist?
The Abusix Policy Blocklist is run by Abusix, a company that provides network abuse management, email security, and threat intelligence services. The Policy Blocklist is part of Abusix Mail Intelligence and is designed for mail systems that want to reject direct SMTP connections from IPs that do not meet common mail-server policy checks.
The list is automated. Abusix scans ranges more frequently when they change often, retests IPs checked through its lookup service, and retests IPs seen through its intelligence network. That automation matters because newly allocated or newly changed IP space can be classified before spam-trap evidence exists.
How do I get removed from the Abusix Policy Blocklist?
Removing your IP from the Abusix Policy Blocklist (blacklist) starts with fixing the underlying issue. Since this is a policy blocklist, the cause is usually missing, generic, or repeated rDNS. Set a unique, non-generic reverse DNS record that reflects the hostname of the sending server. If you are not running a mail server on that IP, you usually do not need to request delisting.
After you correct the rDNS issue, you can request delisting through the Abusix Lookup and Delisting page. You need to create a free account before submitting a removal request, which helps prevent anonymous abuse of the delisting system. Abusix allows delisting for single IP addresses, not entire CIDR ranges.
Removals from this zone are semi-permanent. Abusix says it does not relist a removed address until the rDNS changes again. If the corrected rDNS already meets the policy, the IP can also be removed automatically the next time Abusix scans it. Manual delisting speeds up that process.
Delisting requests are processed immediately. Direct DNS queries usually reflect the change within minutes, while local systems that synchronize a copy of the blocklist data can take up to 15 minutes depending on how they refresh their data.
How to avoid being listed again
For a real outbound mail server, prevention is mostly DNS hygiene and clear server identity. Abusix is not asking every IP to look like a mail server. It is identifying IPs that should use a smarthost instead of sending directly.
- Use a dedicated outbound mail IP where possible, not an IP shared with workstations, web apps, or unrelated customer traffic.
- Set rDNS to the actual mail hostname, then make sure that hostname resolves back to the same sending IP.
- Avoid generic provider templates that include large parts of the IP address in the hostname.
- Do not assign the same rDNS name across a contiguous range of outbound IPs.
- Keep SMTP ports open only where the host is intended to send or receive mail, and route other systems through an authenticated relay or smarthost.
What is the impact of being listed on the Abusix Policy Blocklist?
The impact of being listed on the Abusix Policy Blocklist is medium for a server that sends mail directly to recipient MX hosts. Mail servers that use this blacklist can reject direct SMTP connections from listed IPs. If that IP is your outbound mail server, you can see delivery failures or SMTP rejection messages that mention Abusix.
The impact is limited for IPs that do not send directly. If your device, website server, home connection, or application host sends through an email provider, ISP smarthost, or other outbound relay, the recipient usually sees the relay IP rather than your local IP. In that case, a policy listing is expected and normally does not need action.
Abusix warns that this zone should only be used to check the IP address handing off email to the receiving mail server. It should not be used to check IPs found deeper in Received headers or to score smarthosts incorrectly, because that can create false positives. This makes the Policy Blocklist more specific than a spam-based blacklist that lists hosts after abusive traffic is observed.
Other Abusix blocklists
Abusix Authbl Blocklist
Organization
Abusix
Zone
authbl.mail.abusix.zone
Type
IP
Impact
Medium
Delisting
Manual
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 Spam Blocklist
Organization
Abusix
Zone
black.mail.abusix.zone
Type
IP
Impact
Medium
Delisting
Manual
