Here is how to check the DMARC record for a domain: look up the TXT record at _dmarc in front of the domain, such as _dmarc.cleardue.example, and keep the one that starts with v=DMARC1. Type the domain above and the tool runs that lookup, then reads the policy and every tag back in plain words, including the defaults of the tags you left out.
Only the domain is sent, to Cloudflare's public DNS resolver, and nothing is stored.
How to read the result
Start with the policy. p=quarantine asks receivers to treat mail that fails DMARC as suspicious, and p=reject asks them to refuse it. A t=y tag beside either means the policy is still under test, and receivers apply one level below it.
Then check for a report address. A record with no rua tag sends you nothing, and the summary reports are where you find every service sending as your domain.
A tag the current standard does not define is ignored by receivers. That standard is RFC 9989, which replaced the older DMARC RFC in May 2026 and retired the pct tag, so an older record may still carry it.
Checking a DMARC record in Office 365
Microsoft 365 has no admin page that manages DMARC for a custom domain. Microsoft's guide to setting up DMARC in Microsoft 365 says the record lives at your DNS host, so the check is the same public lookup. Only the onmicrosoft.com domain's record is added in the Microsoft 365 admin center.
Microsoft 365 sends summary reports to a rua address but never failure reports, so a quiet ruf mailbox is not a broken record.
What to do next
Tighten the policy in steps: p=none with a report address, then quarantine, then reject. Between steps, fix each service the reports show failing, and check the domain again after every change.
Then send a test message from each service and paste its headers into the email header analyzer to see whether DMARC passed as the receiver saw it. If mail already bounces under a reject policy, start with the 550 5.7.0 DMARC policy violation page.
