Microsoft controls a huge percentage of personal computing. Indeed one could say they have a finger in every software pie. This is brought forth by their ownership of Windows and all of the Microsoft windows applications. Their Office suite is the industry leader and as such all of the items bundled inside of Microsoft office control their respective software niches as well.
Bundled with every version of Windows comes Internet Explorer and bundled with Explorer comes Outlook Express, Microsoft’s free email client.
Bundled with Microsoft Office you will find Microsoft Outlook. This being a larger far more grand, installable email client.
What both of these applications share, aside from their Microsoft origins is an uncanny ability to louse up. Yes these are the two most widely used email systems in the world and they are fabulously famous for losing email. While it is true most emails are lost due to human error AKA accidental deletion, a huge percentage of the need to recover deleted emails is directly related to errors caused by Outlook and Outlook Express.