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The Spamhaus DBL
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DNSBL Usage Terms
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The Domain Block List (DBL)

The Spamhaus DBL is a list of domain names with poor reputations. It is published in a domain DNSBL format. These domain reputations are calculated from many factors, and maintained in a database which in turn feeds the DBL zone itself.

Who can use the DBL?

The DBL zone is publicly queriable with real-time responses, just like other Spamhaus DNSBL zones. Those running mail server software capable of scanning email headers and message bodies for URIs can use the DBL to identify, classify, or reject mail containing DBL-listed domains. Security professionals and researchers also use domain reputation in their work.

How is the list compiled?

The DBL's reputation database is maintained by a dedicated team of specialists using various data from many sources to craft and maintain a large set of rules controlling an automated system that constantly analyses a large portion of the world's email flow and the domains in it. Most DBL listings occur automatically, although where necessary Spamhaus researchers will add or remove listings manually. DBL data is exchanged with other Spamhaus systems which can result in further listings in the DBL, or in IP addresses being listed in other Spamhaus zones.

How can you use the DBL?

The DBL works well as both a domain URI Blocklist and as a right-hand side block list (RHSBL). It is effective for filtering email during the SMTP session for all header domain checks - rDNS, HELO, MAIL FROM, From, Reply-To, and Message-ID domains - as well as URLs in messages. The DBL is widely used by many parties, both large and small, for checks involving domain reputations, across email and other applications.

DBL is managed as a near-zero false positive list, safe to use by production mail systems to reject emails that are flagged by it. Furthermore, it can be used for tagging, scoring, or foldering. The DBL includes domains which are used in unsolicited bulk email including phishing, fraud, "419," or sending or hosting malware or viruses, as well as other domains with poor reputation due to many heuristics.

Removal from the DBL

Similar to the Spamhaus PBL, the DBL has a monitored, automated, self-service removal system. DBL listings also expire automatically after domains disappear from common use, or as reputation factors change.

Further information

Mail server administrators, spam filter developers, security professionals, and those with listed domains should check the DBL FAQs for more information.
Caution
The DBL lists ONLY domains. Do not query the DBL for IP addresses.



DNSBL Usage Terms
Use of Spamhaus's free public DNSBL service is restricted to low-volume non-commercial users only. To make sure you qualify for free use, please see the terms:
DNSBL usage terms

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