I want Thunderbird 3.1.1 to automatically move old messages to archive. The definition of "old" should vary by folder. E.g., messages in the "Meeting minutes" folder should get archived after 7 days, messages in "newsletters" can get archived after 2 days, but messages in a folder for a course I am taking should not get automatically archived, because I am going to manually move the entire folder to archive once the course is over.

I tried making a filter which moves all messages older than 7 days to an archive folder. It worked when I ran it manually. But I don't know how to make Thunderbird run it automatically once a day on the folder "Meeting minutes".

Any ideas how to do it, with or without filters?