Ten minutes after the connection between a BlackBerry® Enterprise Server and the BlackBerry® Infrastructure closes, the BlackBerry Infrastructure notifies the sender’s BlackBerry device and deletes the message that is not delivered. The wireless network can queue up to 5 undelivered messages for up to 7 days. If more than 5 undelivered messages exist in the queue, the BlackBerry Enterprise Server stores the messages in the BlackBerry Configuration Database. The BlackBerry Infrastructure does not store data to send to devices.

If the BlackBerry Infrastructure is not responding and the connection closes unexpectedly, the wireless network deletes the undelivered messages. The device does not receive the messages and it does not send acknowledgment packets to the BlackBerry Enterprise Server. When the BlackBerry Infrastructure becomes available again, the BlackBerry Enterprise Server resends messages that it did not receive acknowledgment packets for.

When a user sends a message from a BlackBerry® device, the BlackBerry® Infrastructure might not be able to deliver the message to a device immediately if the device is not available on the wireless network. A device might not be available if it is outside a wireless coverage area or if the device is turned off.

If the BlackBerry Infrastructure cannot deliver a message after 10 minutes, the BlackBerry Infrastructure notifies the BlackBerry® Enterprise Server and deletes the message. The BlackBerry Enterprise Server requests a notification message from the BlackBerry Infrastructure when the device becomes available over the wireless network. When the device becomes available over the wireless network, the BlackBerry Infrastructure notifies the BlackBerry Enterprise Server. The BlackBerry Enterprise Server sends the message to the device.

If the message is not delivered after 7 days, the BlackBerry Infrastructure notifies the sender’s device that it cannot deliver the message.