Hold messages and release them later Written by the Hub
A standalone delay mechanism, of the kind MailerQ's own outbox ladder already implements.
In detail
The engine's retry ladder — eleven queues with doubling TTLs, dead-lettering back to the sending queue — does this for delivery attempts. This tool is for delays we introduce ourselves: a scheduled send, a staged release, a queue that should drain slowly. Our warm-up already schedules sends on our side, so the need does not arise today. If it ever does, the ladder pattern is the cheaper answer: it needs no extra process.