Glossary: Attacks and Indicators
SPF (Sender Policy Framework)
Also written: SPF, spf=fail
A domain's list of servers allowed to send its email. `spf=fail` means the sending server is not on that list.
Where the book teaches it
Related terms
DKIM (DomainKeys Identified Mail)DMARC (Domain-based Message Authentication, Reporting and Conformance)Authentication-Results