To better manage the timing of outbound messages, Twilio now offers a validity period feature. This allows developers to set a specific time frame for how long Twilio will attempt to deliver messages before failing with an error. By configuring this feature, developers can prevent late-arriving messages from being sent and ensure that their users receive timely notifications or alerts. The validity period is particularly useful in situations where messages may arrive late due to high message volumes or service outages, and it also helps avoid unnecessary messages being sent when the user has already received the information they need. With this feature, developers can take more control over their messages and ensure that their users receive timely and relevant notifications.