DMARC (Domain-based Message Authentication, Reporting and Conformance) is a DNS TXT record at _dmarc that tells receiving mail servers how to handle messages that fail SPF or DKIM, and where to send reports.

DMARC is published but only monitors (p=none). It does not yet instruct receivers to quarantine or reject spoofed mail.
DMARC record v=DMARC1; p=none