Select Menu button & go to Setup option in the Main Menu
Select E-mail Setting
Scroll down and enter your username & password and select LogIn
Select Add My existing Email Account
Enter Email Address & Email Passward and select Next
After the Processing, Please wait screen you will get the Unable To Configure page select the option I will provide the settings to add to this email account and
select Next
Make sure Internet Service Provider Email (POP/IMAP) is selected and click Next
Select I will provide the settings to add to this email account and click Next
Enter your Email Address, Username: yourusername, Password & Email Server: mail.yourdomain.com.au and click Next
You have successfully added your new email account to your blackberry