Once Thunderbird is started you should see something like this.
Step 1

Step 2
Click the tools menu click account Settings as shown below.

Step 3 Click on the Add Account Button at the bottom

Step 4 Make sure email account is dotted and click next

Step 5 Type your full name and email address

Step 6 Decide if you want to use POP3 or IMAP. Dot the appropriate choice and then type in the incoming server box.
The incoming mail settings are mail.yourdomain.com then click next If you are asked to provide an outing server for mail again use mail.yourdomain.com

Step 7 Use your full email address as the user name.

Step 8 Name your account something like home email or work email

that's it your finished.

Configuring Mozilla Thunderbird Video