Trailhead Support Center : Microsoft Entourage for Macintosh - Adding An Account
Step 1:
 Open Entourage and click on Tools and Accounts.
Step 2:
 Click on the New Button.
Step 3:
 Enter your name and click the right arrow.
Step 4:
 Choose (I already have an email address) and type in the email address and click the right arrow.

Step 5:
Enter your incoming and outgoing mail server and click the right arrow. If you are unable to connect to the smtp server, your ISP may be blocking port 25 from 3rd party use. Contact your ISP if this occurs.

(Replace "domainname.com" with your actual domain name)

Step 6:
 Enter your account ID - this is the complete email address of the account you want to check - for example: username@domainname.com

Enter your email password and click the right arrow.
Step 7:
 Make up any name for the account and click Finish.