New Account
If this is the first time you have opened Mail, you will likely be presented with a screen similar to the one below.
Select Account Type IMAP and fill in your info.
Incoming Mail Server
Enter imap.yourdomain.com and your complete email address
Incoming Mail Security
Leave SSL unchecked
Authentication should be password
Out Going Mail Server
Check Use Authentication and enter in your complete email address and password
Out Going Mail Security
Leave Secure Socketes Layer (SSL) Unchecked
Authentication should be password
Account Summary
Verify your account settings and continue if they are correct
Conclusion
Click Done
Begin enjoying your E-Mail