Abstract: A device and system for checking the presence or absence of mail in a neighborhood delivery mailbox which has a plurality of individual mailboxes. The interrogation and response signals are triggered by remote control from a nearby location, for example from a moving vehicle. A custom identifying means is used to identify a selected mailbox from a cluster of mailboxes. This device and system thereby saves the operator time and provides a secure means of detecting mail from a remote location. The unit may be made miniature, as well as modular. The circuits described can be an integrated circuits or can be made of multiple discrete elements. The hand-held remote interrogator includes an antenna connected to a transmitter, and a receiver which is also connected to an antenna. A microcontroller is also provided to save, store and transmit data responsive to a query from a portable, hand held remote interrogator.