Sending window

The sending window is the span during which a message can go out without waking its recipient or breaking the law. In the US, the TCPA bans automated messages before 8 AM and after 9 PM, in the recipient's local time. In France, phone prospecting is restricted to weekdays between 8:30 AM and 8 PM, and CNIL good practice aligns marketing messages with similar hours. Urgent transactional messages follow more flexible logic.

Beyond compliance, the sending window is an effectiveness question: a text received at 11 PM flips the sender from "responsive service" to "harassment," and a STOP complaint costs more than the appointment gained. A well-designed system separates the first contact — which answers a request made right now and can go out immediately — from automatic follow-ups, always confined to business hours.