Apple’s push mail IMAP service seems to be not compatible with the Windows 8′s mail App. If you want to send and receive iCloud Mail on your Surface Pro/RT tablet, you could try the following step by step to manually configure your email application to sync.
How to setup iCloud Email in Mail App on Surface Pro/RT
* From start screen, tap/click Mail title.
* Within the app, open its Settings, and go to Account > “add account” for configure iCloud account.
* Select “IMAP” and use the setting to type:
Username: use your full icloud mail address (***@me.com)
Incoming Mail Server) information:
Server name: imap.mail.me.com,
SSL Required: on
Outgoing mail server) information:
Server name: smtp.mail.me.com,
Outgoing server requires authentication: yes
Use the same username and password to send and receive email: yes
Turn off SSL for SMTP and on SSL for IMAP.