A method, system and computer program product for instant message communication in a wireless and non-wireless environment. A message is sent from a mobile unit device over a wireless communication network. The message includes a destination address, information associated with the mobile unit device's user, message content and message address. If, according to information previously stored for the mobile unit device's user at the instant message system, the destination address is associated with an instant message function, the associated instant message function is executed at the instant message system using the information contained in the message content, if required as determined by the associated instant message function. If, according to information previously stored for the mobile unit device's user at the instant message system, the destination address is associated with an instant message name, an instant message is created according to the message content and is sent to the user with the associated instant message name. For instant messages sent or received by a mobile unit device with known buddies, the instant message is optimized by tagging the instant message with a routing phone number that is unique to the mobile unit device and buddy combination, whose identity is stored both in the mobile unit device address book and in the instant message routing server.