Since the Cingular network is so fast (and the Causerie IMclient can be set to check for messages as frequently as you like) he's able to receive messages from work in near-real time.
The software started life on Symbian and Series 40 devices before falling out of favor with Nokia, but this WP8 refresh enables cross-platform chatter between those older phones, the newer Lumia range and, as Yahoo Messenger contacts are supported, anything running that IMclient, too.