DMARC Record Checker

What is DMARC?

DMARC (Domain-based Message Authentication, Reporting & Conformance) ties SPF and DKIM together. It tells receivers what to do when authentication fails — and where to send aggregate reports so you can monitor impersonation attempts and broken senders.

The three policies

• p=none — monitor only. Always start here.
• p=quarantine — failing mail goes to spam.
• p=reject — failing mail is dropped. Strongest policy.

Why DMARC matters for cold email

Google and Yahoo's 2024 sender requirements made DMARC effectively mandatory for bulk senders. Without it, deliverability collapses to Promotions or Spam, no matter how good your content is.

Recommended starting record

v=DMARC1; p=none; rua=mailto:dmarc@yourdomain.com; pct=100; adkim=s; aspf=s

Run in monitor mode for 2–4 weeks, then move to quarantine and finally reject.

DMARC checker FAQs

How often should I check my DMARC record?

Check after every DNS change, whenever you add a new sending platform, and at least once a month while you are actively running cold email. Records get overwritten during migrations more often than teams expect, and a missing policy is invisible until placement drops.

Why does my record look valid but reports never arrive?

Aggregate reports only reach the address in the rua tag, and that mailbox has to accept mail from outside your domain. If the address is a distribution list or an alias with strict filtering, reports are silently discarded. Point rua at a real, monitored mailbox or a reporting service.

Can one DMARC record cover subdomains?

Yes. The policy at the organisational domain applies to subdomains unless you override it with thesp tag. Cold email teams commonly keep a strict policy on the root brand domain and a monitoring policy on the sending subdomains until authentication is proven.

Does moving to p=reject hurt deliverability?

Not when SPF and DKIM already pass and align for every legitimate sender. Reject only affects mail that fails authentication — which is exactly the mail you do not want delivered in your name. Move through monitor and quarantine first, confirm reports are clean for two to four weeks, then enforce.