How the check works
DMARC is published as a TXT record at _dmarc.<your domain>. We fetch it, split it into its tags and check that exactly one record starts with v=DMARC1 and that it carries a recognized policy (none, quarantine or reject).
The same lookup also reads the domain's SPF record, since DMARC depends on it. This page focuses on the DMARC half; the email domain checker shows both side by side.
Reading the result
The policy (p=) tells receivers what to do with mail that fails authentication. None means take no action and just send reports, which is the normal first step when you are collecting data. Quarantine asks receivers to treat failing mail as suspicious, usually by sending it to spam. Reject asks them to refuse it.
The subdomain policy (sp=) covers mail from subdomains. If it is absent, subdomains follow the main policy. The percentage (pct=) is the share of failing mail the policy applies to, and 100 is the default when it is missing.
Report addresses (rua=) receive the aggregate reports that show who is sending mail as your domain. A policy without a report address works, but you will not see what it is catching.
Limits worth knowing
This checks that the record is present and well formed. It does not read your aggregate reports or confirm that your sending services pass SPF and DKIM; that needs the reports themselves.
Changes to DNS can take time to reach every resolver, so a record you just published may not appear immediately.
Frequently asked questions
What does p=none mean?
It means receivers should not change how they treat failing mail, they should only report it. It is a safe starting point while you find out who sends mail as your domain, but it does not stop forged mail.
Why does the checker say my record is invalid?
The most common causes are two DMARC records on the same domain, a record that does not start with v=DMARC1, or a policy value that is not none, quarantine or reject. The issues list shows which one applies.
Do I need DMARC if I have SPF?
They do different jobs. SPF checks the sending server. DMARC ties SPF and DKIM results to the visible From address and sets a policy. Large mailbox providers increasingly expect senders to publish DMARC.
Can I check a subdomain?
Yes. Enter the subdomain and we look up its own DMARC record. If it has none, the result says so; receivers then fall back to the parent domain's record.