Importing and exporting Outlook content is really nothing new. But having the ability to export that content in a clean, easy to read HTML format is definitely not something that you would see everyday. Check out HTML Email Archiver for Outlook. If you are a hardcore Outlook user, this could be the option you are looking for.

HTML Email Archiver for Outlook allows you to export and archive your Outlook mail items, including messages, Tasks, Contacts and more. The HTML output is formatted to look very similar to the actual Outlook interface, so it provides familiar way to navigate your archived messages. You can choose to export messages based on date and also select which attachment types to include. The program supports HTML output, as well as compiled HTML archives (.chm) and Mobile Devices. HTML Email Archiver only exports messages, it does not delete any of the items.