Glossary
DNS
Public Suffix List
A community-maintained list of the suffixes under which the public may register names. DMARC uses it to work out where an organisational domain begins, which is why it matters outside browsers.
Defined in publicsuffix.org.
Where this appears
The lessons that use this term, and what each is for.
Email Authentication FundamentalsRelaxed and strictChoose an alignment mode for a domain and defend the choice against its failure cases.DMARC PractitionerThe Public Suffix ListDerive an organisational domain the way a receiver does, and spot where that goes wrong.DMARC PractitionerWhat changes without youName the things that alter your DMARC outcome while your record stays identical.