1. A system for locating content items in a plurality of content sources across different content servers, the system comprising: one or more processors; a memory coupled to the one or more processors; and an e-discovery client application residing in the memory and comprising computer-executable instructions that, when executed by the one or more processors, cause the system to: present a user interface for defining a query for searching the plurality of content sources; receive query parameters, wherein the query parameters are specified by a user; receive a query scope regarding the query, the query scope comprising content sources located on at least two content servers of different types, wherein each content server has a search interface for the content sources; for each content source included in the query scope, execute a search using the corresponding search interface and initiate a segmentation process, wherein the segmentation process comprises iterative searches based on groupings of the query parameters; receive query statistics from searches executed by each of the at least two content servers based on the query parameters; aggregate the query statistics from the at least two content servers and present the aggregated query statistics in the user interface, wherein the query statistics are shown regarding each of the plurality of content sources; retrieve data regarding content items matching the query from the at least two content servers; and present a preview of the content items matching the query in the user interface from the retrieved data.