DNS zone
The part of the DNS namespace one set of authoritative servers is responsible for, such as example.com and the names below it that are not delegated elsewhere.
What it means
A zone is a unit of administration: example.com's zone holds the records for example.com and its subdomains, unless a subdomain is delegated with its own NS records to separate servers. The zone file is the text format from RFC 1035 in which zones are written, one record per line.
When a mail provider asks you to add records, you are editing your zone at your DNS host. Delegating a subdomain (such as mail.example.com) to a sending provider moves its records out of your zone entirely.
A zone begins with an SOA record and lists its authoritative servers in NS records.
Example
$ORIGIN example.com.
@ 3600 IN SOA ns1.dnshost.example. hostmaster.example.com. 2026102101 7200 3600 1209600 3600
@ 3600 IN MX 10 mx1.example.com.
_dmarc 3600 IN TXT "v=DMARC1; p=reject"Related terms
On this site
Sources
What this definition rests on. The wording is ours; the facts are theirs.
- RFC 1034: Domain Names: Concepts and Facilities, section 4.2rfc-editor.org
- RFC 1035: Domain Names: Implementation and Specification, section 5rfc-editor.org
- RFC 9499: DNS Terminology, section 7rfc-editor.org
All 432 terms in the glossaryThe wiki: blocklists and bounce codes