Netscape7
Open the Netscape mail application. Click on the "Edit" drop down menu and select "Properties...".
Enter a check mark in the box for "Use name and password", and enter your user name account.mydomain.com (replace account with the name or word that appears in front of the '@' symbol, and replace mydomain.com with your domain name).
Once all settings have been confirmed, click on the "OK" button in the bottom right hand corner of the window.