Dear friends, This is another question of the type "it has stopped to work after years of perfect service". I do: Tools/Message filters/. The filters are for me (only user). The "Enabled filters" drop-down list shows 238 items with virtually everyone enabled. Then I select folder to be filtered in the input window at the bottom; my "Sent" folder. Then, when I click the button "Run Now", nothing, absolutely nothing, happens. Normally Thunderbird lists messages like "Moved x mails from Sent to folder Y" . Thunderbird 144.0.1 (64-bit) under Windows 10 which was first removed whereupon it was downloaded and reinstalled. Hopefully someone has a suggestion where I can check for the cause of this error? Ch