I believe the problem is that my phone is also reading IMAP email at the same time as Thunderbird on my computer. The phone will read the email and leave it in the inbox. It appears that the process Thunderbird uses is to run the message filters on email entering the system but not already in the inbox, so email already in the inbox is not passed through the email filters. There are several solutions I think that would work. The easiest is to process the emails already in the inbox either before or after the incoming emails are filtered. Another method is to have the option of running message filters ever so often on the inbox and move email with junk tags to the junk folder, or deleted it that option is selected. I believe this is a significant problem that definitely effects a lot of people. Thanks MIke