The Rule-Based Classifier
Lives in src/classify.
A pure function (sender) -> category | null with 5-tier precedence: exact sender → registrable root domain → display-name rules on relay domains → relay account/personal fallbacks → your own domains. No state, no network, no ML.
Origin
Section titled “Origin”87% of 6,551 emails filed with zero machine learning — just rules iterated against recon reports.
Quirk it encodes
Section titled “Quirk it encodes”The session’s naive slice(-2) domain split called amazon.co.uk “co.uk” — fixed with public-suffix-aware tldts and locked in by regression tests.