All versions of Windows 8 and Windows RT include a built in email app named Mail (also referred to as Windows 8 Mail or the Windows 8 Mail app). The Windows 8 Mail app includes support for IMAP and Exchange ActiveSync (EAS) accounts.
This article includes some key technical details of the Windows 8 Mail app. Use the information to help you support the use of Windows 8 Mail app in your organization. Read this article start to finish, or jump to the topic that interests you. Use the reference links throughout the article for more information.
Continue at source.