In Office 2010, the navigation pane replaced the old Find window. And Outlook has as well received an updated search function, and an even more detailed one at that.
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You can begin searching by typing into the text box located over your email previews. As expected, typing in a word or phrase will narrow down the list of results to those that include what you’re looking for. The real magic is found in Tab that now appears in the Ribbon interface.

Using the Search tab you can narrow down your search. You can search only emails from a specific contact, only the subject line, only emails with attachments, only emails sent within a certain time frame, only emails that are unread, only emails that are categorized, and more. You can also open recent searches!

Give it a go!