To set up Mozilla Thunderbird:

Open Mozilla Thunderbird.

Go to Tools > Account Settings

Click Add Account. The Account Wizard will open.

Leave the Email account option selected, and click Next >.

Enter your name as you want it to appear in any messages you send.

Type your e-mail address that you created through Plesk.
For example, your.name@your-domain.com. Click Next >.

Select the protocol of your incoming mail server.
Although Plesk supports both POP3 and IMAP protocols, we recommend that you select IMAP because this leaves your e-mail on the mail server so that it can later be accessed from other locations and by other methods, for example, browser based Webmail.

Specify the mail domain name as the incoming and outgoing mail server (for example: mail.your-domain.com), and click Next >.

In the Incoming User Name box, specify your full e-mail address (for example, your.name@your-domain.com), and click Next >.

Enter the name by which you would like to refer to this account (for example, Work Account) and click Next >.

Verify that the information you entered is correct, and click Finish.

Click OK to close the Account Settings wizard.

Click Tools > Account settings

Select Outgoing Server (SMTP) at the bottom of the list on the left side.

Choose the email address you just added from the list on the right side. Click Edit.

Check Use name and password and type in the email address for User name.

Click OK and OK.