Spam Filters for Thunderbird
See our Thunderbird filters page.
A simple search term for your filter is to look in the Subject for
[PMX:#
We recommend that, at least initially, you move all the filtered messages into a folder, rather than just deleting them right away. This way you can review them for a little while, until you're comfortable that only real spam is being filtered. At that point, you can change your filter to delete these messages as they arrive.
Remember that each number sign ( # ) in the Subject line represents an additional 10% probability. The search term listed above will catch all messages with one or more number signs. If you want to let the messages with just one number sign (meaning a 50-60% probability) get through to your inbox, change the search term to
[PMX:##