Email blocklist · DNSBL · Newly-registered domains MON · 14 SEP 2026

Spamhaus ZRD

Operated by The Spamhaus Project · United Kingdom · Zone zrd.spamhaus.org

About

Zero-Reputation Domains list. Heuristic signal for newly-observed domains in messages, often a strong spam indicator.

Listing criteria

Listing for domains registered within the last 24 hours. Useful as a heuristic input rather than a hard block, since legitimate freshly-registered domains exist.

How to query

For an IP address 1.2.3.4, query reversed-octets-dot-zone:

dig +short 4.3.2.1.zrd.spamhaus.org

A returned IP (such as 127.0.0.2) means listed. Each blocklist has its own set of return codes meaning different things; the operator's documentation explains theirs.

Operator site Delisting / lookup › Return codes ›