Outlook is an email client that allows users to draft and send email messages to clients, colleagues and friends. The application also lets users read their incoming email messages. Outlook gives users the ability to choose how to view email. Part of this functionality is the ability to opt to view email in HTML. This is handy when you receive an email that has components that only appear in HTML.
Double-click on the message that you want to read in HTML. A infobar will appear at the top of the message.
Click on the infobar and choose "Display as HTML" in the list of options. The email message will appear in HTML.