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 and a query scope regarding the query, the query scope comprising content sources located on at least two content servers of different types, 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.