When you use various online tools to check a domain's DMARC record, you might run into one of the errors:
"No DMARC Record found"
"Missing DMARC Record"
"No DMARC record published"
"Hostname returned a missing or invalid DMARC record"
"DMARC policy not enabled"
Any of these messages or similar means one thing: the DMARC check reveals that your domain is not secured and is subject to spoofing attacks. Any spoofing attacker can send malicious emails using your domain, which potentially incur damage to your brand after landing in your customers' mailboxes.
To fix this, you need to start imlementing DMARC, which is the ratified industry standard for email authentication, for your domain. Please refer to: Getting Started With DMARC on this topic.