Cargo CLI — Mailbox Management Mailboxes. A mailbox is a real sending inbox the workspace owns — provisioned through Cargo on a sending domain the workspace also owns, with SMTP and IMAP credentials Cargo holds and uses to deliver outbound mail and to read the replies that come back. Two things follow, and both are easy to get wrong: a mailbox is a recurring monthly credit charge rather than a per-record one, and this domain does not send. It provisions the inbox, ramps it, and reports on what it did; the send itself is the action, under . Version note. Everything on this page is live in the…