I\'m working on a .net solution that is run completely inside a single network. When users make a change to the system, I want to launch an announcement and have everyone else h
You could use a Message Broker, such as ActiveMQ.
Publish your messages to a topic and have the clients register durable subscriptions to the topic, so that they won't miss any messages even if they are not online.
Apache ActiveMQ is a message broker written in Java together with a full JMS client. However Apache ActiveMQ is designed to communicate over a number of protocols such as Stomp and OpenWire together with supporting a number of different language specific clients.
Client platform support includes c# and .net