This blocklist is no longer operational. DNS queries return NXDOMAIN. Remove from MTA configurations to avoid query timeouts.
What it is
Habeas operated a sender certification program and associated blocklist. Certified senders who paid for Habeas certification received a positive signal (whitelisting) while abusers of the Habeas headers were listed. Habeas was acquired by Return Path and the certification program was eventually discontinued.
Ownership history
How it affects SMTP delivery
No impact. The HIL infrastructure is no longer operational.
What causes a listing
N/A, defunct.
How to get removed
No removal necessary.
For the full reference catalog, see the email blocklist directory.
Delisting process in detail
The HIL blocklist targets observed spam sources. Delisting is handled through the operator’s contact form and typically requires documenting the underlying abuse cause plus remediation steps taken. Automatic decay occurs when the observed spam pattern stops, typically within 7-14 days. Response times to manual delisting requests are usually within 24-72 hours for well-documented cases. HIL is a smaller regional blocklist with limited global deployment.
Prevention practices
HIL prevention follows standard anti-abuse fundamentals: authenticated sending (SPF, DKIM, DMARC), disciplined list hygiene (double opt-in, prompt bounce suppression), and complaint monitoring. Because HIL is a smaller blocklist, its impact is limited to receivers that specifically query it. Monitor HIL alongside major public blocklists (Spamhaus, Barracuda) for comprehensive coverage. Gradual IP warmup and confirmed opt-in remain the primary defenses.
Common listing causes
HIL listings correlate with observed spam patterns. Common causes include purchased lists that hit HIL honeypots, compromised shared-hosting accounts, and coordinated spam campaigns. Because HIL operates a smaller honeypot network than major blocklists, listings typically reflect specific abuse rather than broad reputation issues. Purchased or scraped lists containing HIL-monitored addresses are the most common inadvertent cause for legitimate marketing senders.
Related blocklists
HIL operates alongside other regional and smaller-scale blocklists. Enterprise reputation monitoring combines HIL with major blocklists for comprehensive coverage. Smaller blocklists can serve as early-warning signals by reacting faster to specific patterns than consensus lists like Spamhaus. However, for most senders, monitoring the major public blocklists provides sufficient signal without needing to query every smaller list individually.
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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