Provision or reuse a service-scoped Mermail mailbox, then safely find and inspect an expected verification, sign-in, onboarding, receipt, or order-status email for an active third-party workflow. Use when a task needs an email identity, OTP, magic link, passwordless sign-in mail, or an expected transactional inbox message. Do not use for generic inbox cleanup, direct composition, mailbox-agent chat, or triager configuration.
