Windows Live Mail (formerly named Windows Live Mail Desktop, code-named Elroy[1]) is an e-mail client from Microsoft's Windows Live set of products. It is intended to be a successor for Outlook Express on Windows XP and Windows Mail on Windows Vista. The Windows Live Mail version numbering starts at 12 because this application is an advancement of Outlook Express/Windows Mail, not an entirely new application. Windows Live Mail is developed by the same team that wrote Windows Mail.
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An email client, email reader, or more formally mail user agent (MUA), is a computer program used to manage email [1].
Specifically, the term email client may refer to any agent acting as a client toward an email server, regardless of it being a mail user agent, a relaying server, or a human typing on a terminal. In addition, a web application providing message management, composition, and reception functionality is sometimes considered an email client.