-
Switch to the Buckets tab.
Make sure that Subject Header Modification is switched to Off for each bucket you have created.
Make sure that X-Text-Classification Header is switched to On for each bucket you have created.
Back in Mozilla Mail you need to setup folders to move the filtered messages to. Right click on Inbox on the left pane and select New Folder…. Type in the name of one your buckets and press OK. Repeat this for each bucket that you want to be put in a folder instead of your main inbox.
Select Tools→Message Filters… to bring up the Message Filters dialog.
Click New.
In the Filter name box at the top give the filter a name after one of your buckets. You will set up a filter for each bucket you don't want to be in your inbox.
In the next text box area click on the dropdown box that says Subject and select Customize…. This will let you add a custom header. In this dialog type X-Text-Classification, press Add, then OK. If you already added the header, you can skip this step.
Click on the Subject drop down box again and select the X-Text-Classification option you just added.
Click the next drop down box and change it from Contains to Is.
In the third box type in the name of the bucket you are setting this filter up for exactly like you created it in POPFile.
In the lower part of the window, set the drop-down to “Move message to ” and choose the folder from the drop-down next to this.
Click
OK.

Repeat steps 7 through 14 for each bucket.
Close the Message Filter Dialog and you're done.