Glossary
Email authentication
Qualifier
The prefix on an SPF mechanism setting what a match means: + pass (the default), - fail, ~ softfail, ? neutral.
Defined in RFC 7208 §4.6.2.
Where this appears
The lessons that use this term, and what each is for.
Email Authentication FundamentalsQualifiers, and what -all really promisesSay what each qualifier asks a receiver to do, and why the difference between ~all and -all is smaller than it looks.SPF PractitionerSeven results, and what receivers do with eachName the result a given evaluation produces and predict how a receiver treats it.SPF PractitionerDomains that should send nothingWrite the complete record set for a domain that must never send mail.