To setup Mozilla Thunderbird to download your email, please preform the following steps:

1. Open Thunderbird 1.02. From the menu bar, select Tools -> Account Settings...
3. Press the Add Account... button
4. Select Email account, press Next
5. Enter your Name and Email address, press Next
6. Select POP, and for both the Incoming mail (POP3) and Outgoing mail (SMTP), enter mail.domain.com, as shown below:

Note: You will need substitute domain.com with the name and extension of your domain name.

7. Press Next
9. For Incoming User Name, enter your email address, press Next
10. Enter a name for this account, press Next
11. Press Finish