Sender Policy Framework (SPF): How It Stops Email Spoofing

This document is an overview of Sender Policy Framework (SPF) as a foundational email authentication control to reduce domain spoofing and phishing. It explains SPF operation, common misconfigurations (too many DNS lookups, missing includes, multiple records, soft fails), integration with DKIM/DMARC, implementation best practices (use -all, keep records concise, test and update for third-party senders), and its limitations, and it promotes SecurityScorecard’s SCDR for continuous third‑party threat monitoring.