Instant Search helps you to quickly find items in Microsoft Office Outlook. The Instant Search pane is always available in all your Outlook views, such as Mail, Calendar, and Contacts.

Use the following procedure to perform an Instant Search.

Click in the Search field at the top of the folder pane (Inbox or another selected folder). Outlook highlights the search area, as well as the selected folder on the Navigation pane.

Enter the text to include in the search.

As you begin typing, Outlook starts searching. It displays the Search Results (in place of the full contents of that folder).

You can read, reply, delete, or move the items just like from any other folder.

Click the X in the Search field to clear the search.

When you click on the Search field at the top of the Inbox or any other folder, the Search tab appears on the Ribbon. The tools on this Ribbon allow you to refine the search and change the scope of the search.
View the Search tab on the Ribbon.

Use the following procedure to search for messages from a certain sender as an example of an advanced search.

Select the From tool from the Ribbon.

Enter the Sender’s name to replace the highlighted text “Sender Name.”

Outlook displays up to 10 of your most recent searches.

In the Instant Search pane, click Show Instant Search Pane Menu, point to Recent Searches, and then click the search that you want in the list.

Include subfolders in Instant Search

On the Search Tab you get the option to search by current or all subfolders

A Search Folder is a virtual folder that provides a view of all e-mail items that match specific search criteria. For example, the Unread Mail Search Folder allows you to view all unread messages from one location even though the messages may be located in different Mail folders. Default Search Folders

There are three default Search Folders

Categorised Mail includes items that have been assigned a colour category.

Large Mail includes items that are larger than 100 kilobytes (KB).

Unread Mail includes items that are marked as unread.

In addition to the default Search Folders, Outlook includes a list of predefined Search Folders. You can customize a predefined Search Folder with your own search criteria.

You can also create your own custom Search Folder by defining specific search criteria that e-mail messages must meet to be displayed in the Search Folder.

 Note   Search Folders in Microsoft Office Outlook support prefix matching in the text strings that you specify. For example, if you want to include all messages with the word 'rain' in the Search Folder, the Search Folder will also include messages with words like 'raining' or 'rainy' but won't include words like 'brain.

 Important   When you delete a Search Folder, the e-mail messages shown in the Search Folder are not deleted from their original locations, because those items are only viewed in a Search Folder. However, if you open or select one or more e-mail messages shown in a Search Folder and then delete them, the messages will be deleted from the Outlook folders where they were stored.

Switch from plain text emails to rich text or HTML

To check your text formatting and font settings, go to File > Options, and click on Mail from the left screen. To be able to change font and customize text formatting in emails, the Compose in this message format should either say 'HTML' or 'Rich Text'; if it says 'Plain Text', change it to 'HTML'.

Plain text   This is a format that all e-mail applications support. You can set Outlook to open messages that you receive in plain text format only. Plain text doesn't support bold, italic, coloured fonts, or other text formatting. It also doesn't support pictures that are displayed directly in the message body, although you can include the pictures as attachments.

Outlook Rich Text format (RTF) - You can use RTF when sending messages within an organisation that uses Microsoft Exchange; however, we recommend that you use the HTML format. RTF supports text formatting, including bullets, alignment, and linked objects. Outlook automatically converts RTF formatted messages to HTML by default when you send them to an Internet recipient

HTML -  This is the default message format in Outlook. It is also the best format to use when you want to create messages that are similar to traditional documents, with various fonts, colours, and bullet lists. By default, when you select either of the options that allow formatting (HTML or Rich Text), the message is sent in HTML format. So when you use HTML, you know that what you send is what the recipient will see.

Change your global email font settings in Outlook

Go to File > Options, and select Mail from the left screen in the dialog that opened. Then, click on the Stationery and Fonts button.