no windows mail is not included in win 7 because microsoft want everybody who using win 7 to use windows live service. see this article from wikipedia.
Removed features
Main article: List of features removed in Windows 7
A number of capabilities and certain programs that were a part of Windows Vista are no longer present or have been changed, resulting in the removal of certain functionalities. These include the classic Start Menu user interface, some taskbar features, Windows Explorer features, Windows Media Player features, Windows Ultimate Extras and InkBall. Four applications bundled with Windows Vista — Windows Photo Gallery, Windows Movie Maker, Windows Calendar[65] and Windows Mail — are not included with Windows 7, but applications with mostly similar functionality are instead available for free in a separate package called Windows Live Essentials which can be found on the Microsoft website.