Open Outlook Express. Most newer Macs ship with it already installed, look in the "Internet" folder on your hard drive you should see a folder called "Outlook Express".
Click the Tools Menu, and select Accounts. A window will pop up like the one below. Click on the "New" button.
In the "Your Name" screen of the Account Setup Assistant, enter your real name you want to appear on your outgoing mail and click the right arrow.
In the Internet E-mail Address screen, check "I already have an e-mail address..." and enter your zNET address in the box. Click the right arrow.
In the "E-mail Server Names" window, select "My incoming mail server is a POP server", and enter the Incoming and Outgoing mail server names into the boxes below. The server names are on your New Account Quickstart, (if you do not have your Quickstart, contact Tech Support at 800-438-9638 for the correct settings for your account. Click the right arrow.
In the "Internet Mail Logon" window, enter your [an error occurred while processing this directive] email username and email password from your Quickstart into the boxes. You may select "Save password" if you prefer. Click the right arrow.
In the final screen, enter a name for this account (it can be anything you like, such as "My Email" or your username) and click "Finish"
You must now configure outlook to send email with SMTP Authentication. The instructions for doing this are located here.