Name: Your Name (What ever you want)
Email: Your username
Password: Your mac.com account password
Description: MobileMe
Click Next Button
Hostname: Automatically added for iOS & OS X Mail
Username: Your username
Password: Your mac.com account password
Hostname: Automatically added for iOS & OS X Mail
Username: Your username
Password: Your mac.com account password
Click Save Button
Use SSL: Yes
Authentication: Password
Server Port: 993
Use SSL: Yes
Authentication: Password
Server Port: 587
You can login mac.com and Signup for mac.com new account on your iPhone from here.