Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Outlook Express was an e-mail/news client that was included with Internet Explorer versions 4.0 through 6.0. As such, it was also bundled with several versions of Microsoft Windows, from Windows 98 to Windows XP, and was available for Windows 95 and Mac OS 9. In Windows Vista, Outlook Express is replaced with Windows Mail. Windows Live Mail has since been released as the successor to Outlook Express and Windows Mail. Microsoft Entourage, sold as part of Microsoft Office for Macintosh, has replaced the Macintosh version.