DMARC is used to protect your email from email spoofing. DMARC use SPF and DKIM record to validate your email.
DMARC is a TXT record added in your domain DNS.
DMARC record look like
This specifies what to do with incoming email that fails DMARC.
Valid options are none, quarantine and reject.
p=none – used for monitoring. If DMARC fails, remote mail server will sent a mail to “rua” or “ruf” tags specified in DMARC record.
p=quarantine – tell recipient mail server to put message in SPAM folder if DMARC fail.
p=reject – reject mail if DMARC fail.
rf=afrf – Specify type of report you will get.