On your device click on the Windows icon
Select Messaging, it might be on the dropdown or under Programs
Tap Setup E-Mail
Enter your email address
Enter your password
Select NEXT
Uncheck Try to get e-mail settings automatically from the Internet
Select NEXT
Select Your e-mail Provider : Internet E-mail
Next
Enter your full name
Change Account display name if you wish
Select NEXT
Incoming mail server : mail.yourdomainname.com  (be sure to set this to your domain name)
Account type : IMAP4  (very important to change from POP3 to IMAP4 for your mobile device)
Select NEXT
Username : yourname@yourdomain.com (This is your Full Email Address)
Password : Enter your password
Select NEXT
Outgoing SMTP mail server : mail.yourdomainname.com
Outgoing server requires authentication : CHECK
Use the same username and password : CHECK
Select NEXT
Automatic Send/Receive : Manually
    If you set this value to automatic it will use more battery life, this is up to you.
Select Review all download settings
Select NEXT
Message Format : HTML
Message Download Limit : Entire Message
Attachments : Less than 100 KB
Message Format : Plain Text
Message Download Limit : Entire Message
Attachments : Less than 100 KB
Select FINISH