Searching Sorted by Relevance

Hi, 

We would like to be able to search our Sent Items in the Outlook application by the first person in the Sent field. 

As an example: I send an email where the To field contains:

"testing1@microsoft.com; testing2@microsoft.com;". Later on if I were to make a search for "testing1@microsoft.com" then this email would be present at the top of the results. However, if I were to search for "testing2@microsoft.com", then this email will show up as a result AFTER all the emails where "testing2@microsoft.com" is the FIRST email in the "TO" field. 

Thank you.