Here are the settings that you'll need to retrieve email from your main pop account:

Type Of Mail Server: POP
POP server: mail.<yourdomain.com>
POP username: <your account username>
POP password: <the password that you selected when your account was setup>

Here are the settings that you'll need to send email:

SMTP server: mail.<yourdomain.com>
SMTP username: <your account username>
SMTP password: <the password that you selected when your account was setup>

Note: The outgoing server (SMTP) requires authentication (Make sure you select this option when setting up your email client.) i.e. when you send email you'll be prompted for your username and password.