Parse a DMARC record

Split a published DMARC TXT value into its tags.

JavaScript Version 1.0.0 · MIT · by Oveyon · .md

function parseDmarc(record) { return Object.fromEntries(record.split(';').map(tag => tag.trim()).filter(Boolean).map(tag => [tag.slice(0, tag.indexOf('=')).trim().toLowerCase(), tag.slice(tag.indexOf('=') + 1).trim()])); }

Try in the local lab Download function

Input & expected output

Input

"v=DMARC1; p=quarantine; rua=mailto:[email protected]; adkim=s"

Expected output

{
  "v": "DMARC1",
  "p": "quarantine",
  "rua": "mailto:[email protected]",
  "adkim": "s"
}

The edge case

Input

"v=DMARC1;p=reject;"

Expected output

{
  "v": "DMARC1",
  "p": "reject"
}

Know the limits

Tag names are lowercased; values are kept as published. Unknown tags are returned, not validated.
The lab requires v=DMARC1 as the first tag and = in every tag, as receivers discard other records (RFC 7489). Check that p is present: it is the policy receivers apply.

The function above is the implementation used by the lab. The lab validates JSON types and caps size before execution; include equivalent validation when accepting untrusted input in your application.

Source & maintenance

The function above is the implementation the lab runs and the tests exercise. Read the license.

Local fixture scope · Node.js 22.23.2 · reviewed October 28, 2026. No external service is required.

Keep exploring

Convert an email domain to punycode — Keep the local part and convert an international domain to its ASCII xn-- form.
Get the domain of an email address — Take the part after the last @ and lowercase it, for domain checks and grouping.
Mask an email address for logs — Keep the first character and the domain; hide the rest of the local part.