If you are having trouble finding an older message or have a crowded inbox or folder, you can use Outlook’s advanced search features such as searching by folder, location, or sender’s name to locate the message more quickly. 

1.  Find the Search Box, which will be located at the top of your application and click in it.

2. From here, you can choose which specific folder you want to search within by clicking the Current Mailbox drop-down menu that appears to the left of the search box.

3.  You can narrow your search even further by clicking the Hamburger Button next to the arrow in the Search Box.

4. From here, you will be able to search by folder, sender, recipient, subject, keywords and more.

5. Additional filtering options are available by clicking the Add more options button.

6. When you are ready to search, click the Search Button. When you are finished searching, click the X button on the right side of the Search Box.

Tip:  You can click the Save Search button which will automatically create a Smart Folder in the Saved Searches section in the menu pane. This will allow any incoming email or messages meeting that criteria to be filtered and relocated to that folder moving forward.

For the most current information on how to search your inbox and messages, please refer to the following Microsoft support article:  https://support.office.com/en-us/article/find-items-by-doing-a-basic-search-in-outlook-for-mac-53b60f65-25b7-4582-9c5e-4adf16e503a1