Sender Policy Framework—email authentication preventing sender address spoofing.
Sender Policy Framework (SPF) is an email authentication protocol that specifies which mail servers are authorised to send email for your domain. SPF records (published in DNS) list authorised sending IP addresses. Receiving servers check incoming mail against SPF records—mail from unauthorised servers can be rejected or marked suspicious. SPF helps prevent domain spoofing but has limitations (forwarded email breaks SPF). It works alongside DKIM and DMARC for comprehensive authentication.
Why It Matters
The DSC Perspective:
SPF is baseline email authentication. Without SPF, anyone can send email appearing to come from your domain. Implement SPF as a minimum; combine with DKIM and DMARC for full protection.