DMARC is designed to support existing the inbound email authentication processes of a domain. It works in conjunction with both SPF and DKIM. Domain administrators publish a policy that checks whether DKIM, SPF, or both are used for sending mail. It also handles failures when SPF and DKIM verification fails.
While DMARC does not directly check if an email is spam or fraudulent, it does require mail to pass both DKIM and SPF validation.
DMARC can provide powerful reporting capabilities with aggregate reports that capture statistical data, and forensic reports which include messages that failed SPF, DKIM or both.