A relay site associated with a wireless network can send messages between mobile devices associated with the wireless network without having to transmit the messages to a host system. The messages include PIN messages and each of the mobile devices has a PIN address. The relay site includes a relay server for controlling the operation of the relay site, and sending the PIN messages between the mobile devices. The relay site also includes a relay data store having PIN information for users associated with the mobile devices. The relay server can access the relay data store to allow users that use the mobile devices to query the relay data store for PIN information of other users.