Check if a DKIM record is present for your domain, or if you're authenticated with CNAME records to send email from your email service provider.
A selector is a text string at the beginning of your DKIM TXT or CNAME record host/name used to identify or point to a specific DKIM public key.
selector._domainkey.example.com
Follow our step-by-step instructions to setup your new DMARC record.