Before you configure a DMARC record, you must already have both TXT (SPF) and DKIM records configured.
DMARC records are a security protocol that will log any fraudulent attempts to use your domain to send an email. DMARC records are stored in the form of a TXT record with the name ‘_dmarc’.
The value of the record is usually generated by your mail service provider. Or you can use this free tool to generate your own DMARC record.
Note: TXT records are replacing Sender Policy Framework (SPF) records, which are deprecated records. Constellix still supports modifications and deletions of SPF records currently in your account, but new or additional configurations must be in TXT record format.