Subdomain Records vs. Root Domain Records

This guide advises security and email teams on choosing between root-domain and subdomain SPF records to reduce sender sprawl and risk: it explains isolation benefits of subdomain records, when to consider SPF flattening, DMARC alignment implications, practical migration steps (migrate one function at a time, assign ownership, monitor DMARC), and how Sendmarc’s reporting helps maintain visibility and compliance across many domains.