Thunderbird and Junk / Spam Messages

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  • Revision id: 95800
  • Created:
  • Creator: Wayne Mery
  • Comment: article lacked information about whitelist, and also about continuously marking messages as NOT junk
  • Reviewed: No
  • Ready for localization: No
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To deal with the large amount of unsolicited email ("spam" or "junk mail") that most people have to cope with, Thunderbird uses an adaptive filter that learns from your actions which messages are legitimate and which are junk.

Junk filter options

General settings

The filter is enabled by default. You can set system-wide preferences that determine what happens to messages marked as junk. These settings will be used by all your email accounts (although some settings can be overridden in the account settings, as shown below). To access the preferences, click Thunderbird | PreferencesTools | OptionsEdit | Preferences, select the Security panel and then select the Junk tab.

Junk preferences

Per account settings

The configuration in the account preferences for each of your email accounts will override similar settings in the preferences described above. Click ToolsEdit > Account Settings and select Junk Settings in the left pane for the account to see these settings. This section includes the ability to enable addressbooks which will be used as a whitelist. If the sender of a message is a contact in an addressbook that has been enabled for whitelist, then that message will not be marked as junk.

adaptive filter config

Training the junk filter

Tell Thunderbird what is junk

In order for this filter to be effective, you must train it to recognize the messages that you consider to be junk and the messages that you consider to be not junk. So you will want to mark messages as junk, not delete them.

You can mark messages as junk by clicking in the "junk" column in the message list:

junk message list

You can also mark messages as junk in the message pane by clicking the Junk button on the message header:

junk message window

You can also use the small case j key to mark messages as junk.

You will need to train many messages so that the adaptive filter has enough data, including messages that are NOT junk. (more about that below)

Tell Thunderbird what is NOT junk

It as just as important to tell the filter what messages are not junk.

First, during the early learning stages you will want to frequently, perhaps daily, check your Junk folder for messages that have been incorrectly classified as junk by clicking on the Not junk button, or using the upper case J on your keyboard. After the first week you should also check the junk folder for messages that are incorrectly marked as junk, perhaps weekly.

Secondly, very important, you will want to continuously train the filter by marking a quantity of good messages as not junk, for example messages in your Inbox. You must use the keyboard upper case J, because the "Not Junk" button appears only for messages that have already been classified as junk. Marking several messages per week will be sufficient.