Thunderbird gets messages for that account only.Select the account that you want to update.Click the arrow at the right side of the Get Mail button.

Thunderbird updates all your e-mail accounts.In the main Thunderbird window, click the Get Mail button.Get new email messages for all your accounts at once.There are several ways to manually look for new email using Thunderbird. If you want Thunderbird to look for new email at certain time intervals (maybe every 20 or 30 minutes), select the Check for new messages every 10 minutes check box and enter a different number into the text box.De-select this check box if you don't want Thunderbird to get messages at start up.

Click the Check for new messages at startup check box to have Thunderbird get new email when you launch it.

Click Server Settings to open the dialog box where you tell Thunderbird when to look for new mail.

On Linux, go to the Edit menu and click Account Settings.

On Windows and Mac OS, go to the Tools menu and click Account Settings.

Let's take a look at how to configure Thunderbird's refresh schedule and at how to get emails manually. You can also manually check for new messages in your account. Typically, Thunderbird puts the messages into your Inbox folder. By default, it looks for new messages each time you start it and then it rechecks at ten minute intervals. When you first set up your email accounts, Thunderbird configures itself to get new email automatically.

Thunderbird not receiving some emails