Open Thunderbird. Click on the Tools Menu, and then Accounts. In the left column, click on Account Actions and then Add New Account. Or, if this is the first-time opening Thunderbird the system will automatically launch the Account creation wizard.

Put in your Name, your Email Address, and your Password, and check the Remember Password button if appropriate. Click Continue.

If Thunderbird successfully can reach mail.lisco.com it will discover all the settings, press Done!