A first refusal now names three things: what triggered it (a message that pitches to someone who did not ask, or goes to recipients with no prior thread, or reads as marketing), what passes (a reply in an existing thread, or a confirmation, receipt, notification, reminder or verification), and how to check without sending — send with a test key or press Send test, and the verdict comes back with nothing transmitted and nothing billed.
Six near-identical copies of that message had drifted apart across five send routes, so only one of them ever got fixed. There is one now.