An integrated messaging system for performing various types of messaging across different types of networks, including integrated user interfaces and administrator interfaces. Embodiments include a communication server that couples among networks of different types, and an interface module that couples to the communication server. The interface module may be hosted on a messaging server of a network. The interface module pulls various user information from the messaging server, including information relevant to at least the network that includes the messaging server. A cache couples to the communication server and to the interface module to hold information from the communication server and/or the user information pulled from messaging server. The interface module directs a message from the messaging server and/or the cache to at least one device on the networks using the user information.