Email Verification Waterfall

Every address runs a multi-vendor verification waterfall, and disagreement between vendors is itself information. A single verifier is a single point of failure with a commercial incentive to say yes — running verifiers in sequence means each one's blind spot is covered by the next.

The order has a logic. The flow opens with a general verifier — MillionVerifier or LeadMagic, and the two are interchangeable in that slot. The middle slot flexes: whichever vendor fits the list. The last slot never flexes: it is always a catch-all-capable verifier — the BounceBan and DeBounce class, with OrbiSearch, Reoon, and TryKitt in the same family — because the waterfall's whole job is to end with the unknowns and the catch-alls resolved, and the anchor slot belongs to the most dependable vendor in the flow.

Catch-all addresses get their own isolated sending lane — separate domains, separate inboxes, a dedicated tag — so a riskier class of address can be worked without putting the primary sending reputation behind it. They're worth contacting, but not with the reputation everything else depends on.