How to configure Mozilla Thunderbird to move spam to the Junk folder automatically.

  1. Click on Tools, Message Filters…. This will bring up a window called Message Filters.
  2. Select your GreenNet account in Filters for.
  3. Click on the New… button. This will bring up a window called Filter Rules.
  4. In Filter Name type GreenNet Anti Spam filter.
  5. Select Match any of the following.
  6. In the first drop-down list select Customize…. This will bring up a window called Customize Headers.
  7. Enter X-Spam-Level under New message header: and press the Add button. You should have X-Spam-Level in the list below now.
  8. Press the OK button to close the Customize Headers window and return to the Filter Rules window.
  9. Now select X-Spam-Level from the first drop-down list (if you cannot find it return to step 6.).
  10. 0. Select contains from the next drop-down list.
  11. Enter 5 asterisks into the field right next to contains – it should look like this *****. You can change the sensitivity of the filter by adding or removing asterisks (*). More asterisks will mean that it filters out less spam. Less asterisks will catch more spam but also increase the possibility of ‘false positives’.
  12. Tick Delete the message in the lower section of the window entitled ‘Perform these actions:’.
  13. Click OK.

Alternatively, you can combine it with the Thunderbird adaptive (learning) junk mail filter. This doesn’t give quite such a control over the sensitivity of the filter. Go to Account Settings (under Tools) and look at the Junk Settings, and tick “Trust mail headers set by” and make sure “SpamAssassin” is selected.

Thuderbird Junk Mail controlsThuderbird Junk Mail controls

You should still train Thunderbird by clicking the “Junk status” (flame) column, and then check it’s working before selecting “Move new junk messages to” “Junk folder”.