An agency-ready digital package for repeating list triage across client accounts. Includes the bounded 500-row pre-filter kit, an agency runbook, and a plain-language usage boundary. Use syntax/typo, public DNS/MX, disposable, and role signals before a separately approved paid verifier; preserve ambiguous results as unknown. No SMTP probing, mailbox login, email sending, enrichment, mailbox-existence claim, deliverability guarantee, implementation, or list handling. Buyer-owned lists only.