Free tool

DMARC record generator

Answer three questions. Get one line to paste into your DNS. No sign-up.

New to DMARC? Choose "Nothing yet".

Only used with spam or block. A smaller share is safer while you test.

Optional. Harbour customers get their own reporting address when they add a domain.

TypeTXT
Name_dmarc
v=DMARC1; p=none

Where to paste it

Create a new TXT record. The name (sometimes called host) is _dmarc; the value is the record above. Leave TTL at the default.

  • Cloudflare: DNS → Records → Add record → Type TXT, Name _dmarc.
  • GoDaddy: My Products → DNS → Add New Record → TXT, Host _dmarc.
  • 123-reg: Manage DNS → Advanced DNS → add a TXT record with hostname _dmarc.
  • Squarespace (formerly Google Domains): Domains → DNS → Custom records → TXT, Host _dmarc.
  • Microsoft 365 DNS: Settings → Domains → your domain → DNS records → Add record → TXT, name _dmarc.

Some hosts add your domain to the name automatically. If yours shows _dmarc.yourdomain.com.yourdomain.com, enter just _dmarc.

Which policy should I choose?

If you've never had DMARC, start with watch only (p=none). It changes nothing about delivery, and the reports show you who sends email as you. Move to quarantine and then reject once every real sender passes; see getting to p=reject safely.

Next steps

  1. Paste the record at your DNS host.
  2. Wait a few minutes, then run the DMARC checker to confirm it's live.
  3. Read the reports, or let Harbour read them for you, and fix any sender that fails.
  4. Tighten the policy in stages.

Keep it fixed

Settings drift. A new mailing tool, a DNS move or an expired key can quietly undo the fix. Harbour reads the daily reports that inbox providers send about your domain and tells you in plain English when something breaks.

Start monitoring