To easily search for Email messages, click the Email Search icon that can be found on the Search Ribbon:
This will give you more specific options for searching email messages:
This page allows users to quickly narrow a search to include only email messages (msg and eml files). Users will have the options to search the Subject, From, To, and Cc fields, as well as Sent dates. Users can also search for email messages with attachments and can sort the search results by either Sent date or Subject.
Clicking the "Me" link will insert your account name and email address into the search box.
NOTE: In the resulting searches, you may notice that the Sent By field is the same as the Modified By whereas the From field will only display when it is extracted and parsed from the message header. In many cases these two fields will match.