Glossary
Email authentication
Softfail
The SPF result from a ~ qualifier: the host is not authorised, but the domain owner is not asking for rejection. Receivers treat it as weak negative evidence rather than a instruction.
Defined in RFC 7208 §8.4.
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.