Outlook Express is a scaled-down version of Microsoft's commercial PIM/e-mail Outlook client. What Express lacks in overall functionality, it more than makes up for in raw speed and seamless integration with v4 and later of Internet Explorer.
Outlook Express is no slouch when it comes to features, either; the younger sibling comes extremely close to matching Outlook feature for feature in terms of Internet e-mail capabilities. Express lacks only Outlook's optimized mail access for LAN workgroup users, Internet fax capabilities, and a few additional high-end mail features.
Outlook Express' niche is as an integrated mail companion to Internet Explorer. In this role, Outlook Express stands out for its ease of use, rich feature-set, advanced security capabilities, and appealing interface.
