Surface RT is running Windows RT, but this version does not come with Outlook. Microsoft haven’t developed a different type of ARM processor for Outlook, so there is no an Outlook app that is compatible with Windows RT. To access your Outlook on the tablet, you need to use the built-in Mail app or other 3rd party email apps from store.
Another different versions is the Surface Pro. It does run a regular version of Windows 8 system. Users are able to install Outlook, Office suite and other softwares.
Updates: There is a workaround for fixing the problem using Outlook.com.
Link:Setup POP3 Email with Windows 8 Mail Using Outlook.com
News: You can also try the TouchDown Outlook-Exchange mail app to setup outlook on Windows RT.