Glossary
Email authentication
SPF
Sender Policy Framework — a DNS record listing which hosts may send mail using a domain in the SMTP envelope sender. It authorises hosts, not messages, and says nothing about the From header a reader sees.
Defined in RFC 7208.
Where this appears
The lessons that use this term, and what each is for.
Email Authentication FundamentalsWhat SPF asserts — and what it does notState the exact claim an SPF record makes, and name the identity it says nothing about.Email Authentication FundamentalsThe shape of an SPF recordFind a domain’s SPF record and break it into its terms.SPF PractitionerThe algorithm, term by termWalk any evaluation in the order a receiver walks it, and say where it stopped.Email Security PractitionerFifteen minutes of public DNSEstablish a domain’s entire published mail posture without any access to it.Domain Trust ArchitectureWhere each control sitsMap every control you have learned onto the surface it defends.