The screenshots in this article are from Office 2016 - your version may look slightly different.
The Outlook Advanced Find tool can be used when a standard search using the search bar either brings back too many results, or does not seem to find what you were looking for.
1. Open the Search Tools menu
Click in the Search bar. On the Search tab at the top of the screen, click Search Tools > Advanced Find. This will bring up the Advanced Find window.
2. Choose a field to search on
Click the Advanced tab in the Advanced Find window. Under 'Define more criteria', click the 'Field' button and then click 'All Mail Fields'. This will show a menu of fields you can use to search on, such as From, To, Received, Subject, etc.
3. Define search criteria
Choose a field from the All Mail Fields menu, then choose a condition and value to search for.
E.g From | Contains | Katie will search for messages from someone whose name includes "Katie". You can add as many conditions as you need to narrow down your search, such as:
Received | between | 01/02/17 and 31/02/17
Message | contains | budget
To | contains | Rob
This will search Outlook for all messages from someone with "Katie" in her name that was received in May 2013, contains budget in the body of the email and was also sent to someone with "Rob" in his name.
4. Run the search
When you are happy with your search criteria, click 'Find Now' to run the search.