Look up and parse a domain's DMARC record and policy online, in your browser.
Find a domain's DMARC record and read its policy (none, quarantine or reject), subdomain policy, percentage and reporting addresses. DMARC builds on SPF and DKIM to stop spoofing.
Start at p=none to monitor, then move to quarantine and finally reject once you trust your mail is aligned.
In a TXT record at _dmarc.yourdomain.com — the tool looks there automatically.