TXT Record
Stores arbitrary human-readable or machine-readable text in DNS. The workhorse of email authentication, domain verification, and policy publication.
The DNS Swiss Army Knife
TXT records were originally designed for human-readable text associated with a hostname (RFC 1035). Over time, they became the standard mechanism for publishing machine-readable policy data — because any operator with DNS access can publish a TXT record without needing a new record type to be implemented by all DNS software.
TXT record values are one or more quoted strings up to 255 characters each. For longer data (like long DKIM public keys), multiple strings within the same record are concatenated by the resolver. Multiple TXT records on the same name are valid — and required in some cases (e.g., multiple DKIM selectors).
- Each quoted string: max 255 bytes of content
- Multiple strings in one record are concatenated:
"part1" "part2" - Multiple TXT records on the same name are all returned
- Only one SPF record allowed per name — multiple v=spf1 records = permerror
- DKIM selectors each get their own subdomain, so multiple DKIM TXT records don't conflict
What TXT Records Are Used For
Authorizes which servers may send email for the domain. Published at the zone apex.
Public key for verifying DKIM email signatures. Published at selector._domainkey.domain.
Email authentication policy and reporting. Published at _dmarc.domain.
Proves domain ownership to Google, Microsoft, GitHub, and other services.
Brand Indicators for Message Identification — attaches a logo to authenticated email.
Mail Transfer Agent Strict Transport Security — enforces TLS for inbound email delivery.