EmVis is an information visualization tool for the analysis of e-mail exchange among people in an organizaiton. A company-specific organizational hierarchy is used to provide the basic layout for a graph-based visualization of e-mail exchange. Various parameters are mapped to the nodes and edges in this graph: rank within the company, frequency/amount of e-mail exchange between subjects, possibly information content. The system we describe also supports more general graph-based visualizations not necessarily based on a company's hierarchy; it is possible to use EmVis for queries regarding any group of employees and the e-mail exchange among them. We employ geralizations of traditional information visualization concepts, such as cone tree and hyperbolic space representations