Validate an email address and return structured signals: RFC syntax validity (isSyntaxValid + reason if not), the normalized address with split local/domain, and boolean flags for isDisposable (throwaway/temp-mail domain), isRoleAccount (info@, support@, admin@, …), and isFreeProvider (gmail/outlook/yahoo/icloud/…). With checkMx (default true) it also reports hasMxRecords — whether the domain publishes MX records, looked up live via DNS-over-HTTPS — plus the MX hosts. IMPORTANT: this is NOT a deliverability or mailbox-existence guarantee (catch-all domains, greylisting, and privacy relays make that impossible to assert from a single lookup); hasMxRecords reflects DNS MX presence only. Useful for signup-flow hygiene, lead scrubbing, and flagging disposable/role addresses before sending.