You must have an active network or Wi-Fi connection to receive an alert. If you do not have an active or strong enough connection when an alert is sent, the alert will be queued for a limited time and be sent to you once your device is connected. Examples of offline situations include: No Network connection (Computer) the device being in airplane mode (cellphone) you have your cellular or Wi-Fi turned off you are out of range of a local cellular tower or Wi-Fi base station you are in a dead zone where the cellular or Wi-Fi signal is impeded