Guide

Spamhaus DBL

Spamhaus DBL (Domain Blocklist)

Overview

The Spamhaus Domain Blocklist (DBL) is a list of domain names with poor reputation, published in a domain DNSBL format. It is operated by Spamhaus, an international non-profit organization founded in 1998.

The DBL evaluates many factors for domain inclusion, including domain age, sending patterns, spam activity, cybercrime involvement, and other reputation signals. These domain reputations are calculated from many factors and maintained in a database by a dedicated team of specialists. The DBL zone is continually updated and served from over 80 mirrors worldwide.

Note: The DBL ONLY lists domains. No IP addresses are listed in the DBL. For IP-level listings, refer to Spamhaus SBL, XBL, PBL, or ZEN.

Impacts

This listing occurs at the domain level (not IP level). A Spamhaus DBL listing is considered Tier 1 — Critical impact. It is one of the most widely used domain blacklists globally, consulted by major ISPs, mailbox providers, and enterprise security platforms.

When your domain is listed on the DBL, emails containing links to your domain will be blocked or heavily filtered, even if your sending IP is clean and your email authentication (SPF, DKIM, DMARC) is properly configured. DBL data is also exchanged with other Spamhaus systems, which can result in further listings or IP addresses being listed in other Spamhaus zones.

Mitigation Process

To better understand the potential problems that caused the listing, visit the Spamhaus DBL page and use the Spamhaus IP and Domain Reputation Checker to look up your domain. Once you have reviewed, you should then:

  1. Find and correct the root cause of the listing (e.g., spam activity from your domain, compromised website being used for phishing or malware distribution, snowshoe spamming, or poor domain reputation practices).
  2. Use the Spamhaus Lookup page to submit a delisting request for your domain. Follow the instructions returned by the lookup form.
  3. Wait for verification. Listings will expire automatically when the domain stops matching the criteria that caused the listing, but this can take time. A formal removal request may accelerate the process.

Important: The issue must be resolved prior to requesting removal. Submitting a removal request before fixing the root cause results in an escalated listing that is significantly harder to remove. Domain reputations are built over time, and building a good reputation takes longer than building a bad reputation. Spamhaus may decline the removal request if they believe the actions taken are not sufficient to prevent future abuse. Excessive removal form abusers may be blocked from submitting further requests.