What it is
Abusix Mail Intelligence is a family of DNSBLs covering IP addresses, domains, and exploit sources. The main zone (block.abusix.zone) consolidates spam source data, exploited host data (similar to Spamhaus XBL), and domain abuse signals. Abusix also maintains separate zones for specific threat categories. Data is sourced from abuse reports, honeypots, and threat intelligence feeds.
How it affects SMTP delivery
Abusix zones are queried at MTA connection time or during content scanning depending on the zone. IP zone queries return 550 rejections at supporting MTAs. Domain zone queries raise spam scores in content filters. Abusix is increasingly used by cloud mail providers and enterprise gateways.
What causes a listing
Listings occur when an IP is identified as sending spam or hosting exploit infrastructure, when a domain is used in phishing or malware campaigns, or when an IP generates abuse reports that Abusix's feeds pick up. Compromised servers and open relays are common causes.
How to get removed
Use the Abusix portal at lookup.abusix.zone to check listing status and submit removal requests. Separate forms exist for different zone types. Removal requires demonstrating that the abuse has stopped.
For the full reference catalog, see the email blocklist directory.
Delisting process in detail
Abusix Mail Intelligence operates multiple zones targeting different abuse patterns: AuthBL (compromised authenticated senders), Botnet (command-and-control infrastructure), Exploit (compromised hosts), and Policy (policy-based ranges). Delisting is handled through lookup.abusix.com and typically requires demonstrating that the abuse cause has been remediated. Abusix responds to well-documented delisting requests within 12-24 hours. Enterprise customers of Abusix Mail Intelligence can request expedited review through their support channel. Automatic decay occurs when the observed abuse pattern stops.
Prevention practices
Abusix specifically targets authenticated abuse (compromised customer accounts on shared hosting or SaaS platforms), so prevention requires strong account security: mandatory 2FA on all mail-sending accounts, credential-stuffing protection on login endpoints, rate limiting on outbound sends per authenticated account, and anomaly detection for unusual sending patterns. Shared-hosting providers and ESPs are particularly exposed to AuthBL listings when a customer account is compromised and used to blast spam through legitimate infrastructure.
Common listing causes
Abusix AuthBL listings usually indicate a compromised customer account: attackers steal SMTP credentials via phishing or credential stuffing, then use them to send spam through the provider’s authenticated relay. The provider’s IP gets listed because the abuse originated from their infrastructure even though the credentials were compromised customer accounts. Prevention requires 2FA, credential monitoring, and outbound rate limiting per account. Abusix’s Exploit zone catches compromised web servers being used as spam relays, similar coverage to Spamhaus XBL.
Related blocklists
Abusix Mail Intelligence competes with Spamhaus’s commercial data feed and with Cisco Talos for enterprise reputation licensing. Abusix’s data feeds several major mailbox providers and appliance vendors, so an Abusix listing has broad downstream impact. The company was founded by former Spamhaus and blocklist community members, and their data collection methodology is similar to Spamhaus but with independent operations. Enterprise mail administrators typically monitor Abusix alongside Spamhaus for the strongest coverage of authenticated-account abuse and compromised infrastructure.
About the Author
Alaa · LinkedIn
Email infrastructure specialist with 8+ years of hands-on experience in SMTP, deliverability, and email verification. I’ve configured and troubleshot mail systems across Postfix, Exchange, and cloud relays, managed IP reputation and warmup campaigns, and built verification pipelines processing millions of addresses. My work spans DNS authentication (SPF, DKIM, DMARC, BIMI), bounce handling, blocklist monitoring, and compliance frameworks including CAN-SPAM and GDPR. I write every article on SMTPedia to give email professionals, developers, and marketers the accurate, RFC-grounded reference they need.
About SMTPedia
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