Thunderbird - general instructions (Windows)

Mozilla Thunderbird is an open-code, free e-mail program. The newest English version of Thunderbird can be downloaded free of charge on the Mozilla project website, and the Finnish version on the Mozilla Europe website.


Detailed help

Getting started

  • After the program starts, a view opens with the mail folders one below another in the left. Local Folders refers to the mail folders on your own computer, stored ONLY locally to said computer.

Reading new e-mail

  • By clicking the Inbox section under the mail account, a connection to the e-mail server is initialised.
  • The mail server requires identification when logging in to the program and when sending a message for the first time. You can allow Thunderbird to remember your password by ticking the section Use Password Manager to remember this password and you will not have to enter your password at all. This feature should not be used if another person uses the same computer or e-mail program.

Thunderbird basic features

  • New messages are retrieved from the server by clicking Get Mail, and writing a new e-mail is started by clicking Write.

  • Reply to a message by clicking Reply. Clicking Delete marks the message to be destroyed.

  • The messages marked to be destroyed are deleted for good by selecting Menu > File > Compact Folders in the top right corner.

Filtering junk mail on Mozilla Thunderbird

Thunderbird has a built-in support for filtering junk mail. First, the user trains the filter to identify junk mail by marking it with the Junk option. Based on the user's selections, the filter learns to identify junk mail on its own, and it can be set to automatically move junk mail to a junk folder.

  • Select Menu > Options > Account Settings

  • Select Junk Settings under the account you wish to edit. When the Enable adaptive junk mail detection option is ticked, automatic junk mail filtering is active.

  • Trust junk mail headers set by: You can also use ready-made junk mail lists, such as SpamAssassin. In that case, the known junk mail found in the list is automatically deleted.
  • In the Move new junk messages to: section, you can select the folder to which all messages identified as junk mail are moved. You may select the Junk folder or any other folder.
  • Remember to check your junk mail folder regularly as sometimes normal mail may accidentally be moved there. It is also advisable to empty the folder from time to time. You can also set the junk mail to be automatically deleted after a specified period of time.


  • To achieve the best results in filtering, it is important that the messages that have passed the filter are manually marked as junk mail with the Junk option, and the normal messages incorrectly classified as junk mail are removed from the junk mail folder with the same option (in these cases called Not Junk). The more practice the automatic filter gets, the better it identifies junk mail automatically.

Deleting messages

Unnecessary messages should be deleted regularly to free mailbox space. A message can be deleted in the following manner:

  • Select a message and click Delete.

  • The message is not permanently destroyed but moved by default in the Trash folder.
  • You can destroy the messages permanently by clicking on the Trash folder icon with the right mouse button and selecting Empty Trash in the opening menu.

  • Confirm deletion by clicking Yes.

  • You can affect the functions of the Delete option by opening Options > Account Settings in the top right corner menu in the program window.

  • Select the Server Settings tab (1) from the opening window.

  • The messages deleted by default are moved to the Trash folder. You can change the settings in section (2).
  • Finally, click OK (3).

Shutting down Thunderbird

  • Thunderbird is shut down from the menu in the top right corner.