University Computer Help Desk

Before You Begin

Thunderbird includes adaptive junk mail controls. This anti-spam feature will evaluate new email messages you receive to determine whether or not they are junk (i.e. suspected spam).

By default, Thunderbird's adaptive junk mail controls are turned on. When Thunderbird identifies an email as junk, it flags the message with an icon that looks like a flame. (Figure 1)

Once you are comfortable with Thunderbird's ability to accurate identify spam emails, you should configure Thunderbird to automatically move spam emails to your Junk folder.

Training Thunderbird Makes it Better at Identifying Spam

When you first start using Thunderbird, it might only catch a few spam emails. To improve Thunderbird's effectiveness, locate the spam emails it missed and mark them as junk mail.

1. Find a junk email message in your Inbox.
2. To mark the message as junk, do one of the following:
   • Click the dot to the left of the Date column.
   • Right-click on the message and choose Mark > As Junk.
   • Select the message, and click the Junk button in the message pane.
3. The dot to the left of the date is replaced with a flame icon, which means the message is flagged as junk. (Figure 1)
4. After marking a message as junk, you may delete it or manually move it to the Junk folder.

As you continue to train Thunderbird, it will get better at identifying spam. Thunderbird needs to receive a combination of spam emails and legitimate emails to improve its junk mail recognition.

Automatically Move Spam to the "Junk" Folder

Thunderbird can be configured to automatically move spam emails to the Junk folder. We recommend you evaluate and train Thunderbird's adaptive junk mail controls first. After you are confident Thunderbird is accurately identifying junk mail., configure it to automatically move junk email to the Junk folder.

When Thunderbird Marks a Message as Spam...

To configure Thunderbird to move junk email it identifies to the Junk folder, do the following:

1. Open Thunderbird.
2. Click Tools > Account Settings....
3. Click Junk Settings on the left, underneath your account.
   • If Thunderbird is configured with more than one account, click Junk Settings under the account on the left for which you would like to enable automatic junk mail handling.
4. Put a check mark next to Move new junk messages to:.
5. The first option, "Junk" folder on: <YourAccount>, is selected by default. We recommend you use this setting.
6. Click OK.

When you check email with Thunderbird, it will evaluate each email message that you receive. If it thinks the message is junk mail, it will move the message to your Junk folder.

When You Mark a Message as Spam...

To configure Thunderbird to move email you mark as junk to the Junk folder, do the following:

1. Open Thunderbird.
2. Click Tools > Options....
3. Click Security at the top of the window.
4. Click the Junk tab.
5. Put a check mark next to When I mark messages as junk:.
6. The first option, Move them to the account's "Junk" folder, is selected by default. We recommend you use this setting.
7. Click OK.

When you mark a message as spam, Thunderbird will move the message to your Junk folder.

False Positives or Missing Email

Thunderbird might occasionally make a mistake and mark a legitimate email as spam. You should periodically open your Junk folder and browse its contents to make sure no real emails were accidentally marked as spam.

1. Open your Junk folder.
2. Locate a legitimate email that should not be classified as junk mail.
3. Mark the message as "not junk" by doing one of the following:
   • Click the flame icon to the left of the Date column.
   • Right-click on the message and choose Mark > As Not Junk.
   • Select the message and click the Not Junk button on the tool bar.
4. Move the message back to your Inbox or to another folder.

Cleaning Up Your Junk Folder

You should periodically delete all the junk emails in your Junk folder. Thunderbird does not need them. Once you've marked a message as junk, the spam information is stored in a training.dat file.