1. Click Mail (top left) and choose Preferences.
  2. Click Accounts -> Add Account.
  3. Choose Other.
  4. Enter your Full Name (as you want it to appear on emails), Email Address, and Password.
  5. Click Next, Apple Mail should say account needs to be manually configured.
  6. Choose IMAP for Account Type.
  7. Enter your Mail Server, User Name (your full email address), and Password.
  8. Enter your SMTP Server, User name (your full email address), and Password.
  9. Click Next and your done!