REFUSED
The DNS response code (RCODE 5) meaning the server declined to answer for policy reasons, such as a query for a zone it does not serve.
What it means
A server answers REFUSED when policy stops it from answering: an authoritative server asked about a zone it is not configured for, or a resolver that only serves its own network receiving a query from outside.
The first case is the one domain owners meet. If a domain's NS records point at a DNS host where the zone was never created (or was deleted), those servers will typically refuse queries for it and the domain's records, mail ones included, fail to resolve.
Check the delegation at the registrar against the zones that actually exist at the DNS host.
Related terms
On this site
Sources
What this definition rests on. The wording is ours; the facts are theirs.
- RFC 1035: Domain Names: Implementation and Specification, section 4.1.1rfc-editor.org
- RFC 9499: DNS Terminology, section 3rfc-editor.org
All 432 terms in the glossaryThe wiki: blocklists and bounce codes