email spoofing
https://dmarc.org/resources/deployment-tools/
Set up TXT record, set to monitor only for now.
add records from your cPanel's "Zone Editor" > Manage > Add the record required ( TXT in the case of DMARC )
https://www.thcservers.com/portal/viewticket.php?tid=888905&c=E9PGPfta