PST Capture is used to discover and import Outlook Personal Folder (.pst) File Format files into Exchange Server and Exchange Online. 

PST Capture helps an organization that wishes to gain more control over their email data repositories by placing them into Exchange. By optionally installing PST Capture Agents on target machines, administrators can determine where .pst files are located and who their file owner is via the PST Capture Console. Administrators can import .pst files via Import Lists to Exchange Server or Exchange Online. Data can be directly imported into the primary mailbox or associated archive mailbox. 

Source:  http://www.microsoft.com/en-us/download/details.aspx?id=28767