Web, domains and email
DMARC
Abbreviation for Domain-based Message Authentication, Reporting and Conformance
In short and in plain language
DMARC is an entry in the settings of a domain.
It tells recipients how to handle emails that fail certain checks.
The domain holder can also get reports about such emails.
Definition
DMARC is a DNS record of a domain that tells recipients how to handle emails that fail the SPF and DKIM checks. In addition, the domain holder can receive reports about such emails.