I have this error in my spamtrain.log:

20130317234501 Starting spam/ham cleanup
[] WARN: Spam/notspam messages must have attachments (skipping /service/user/spam.df3laqvx1@mail.example.com/?id=328)
[] INFO: Total messages processed: 10
[] INFO: Total messages processed: 0
20130317234510 Finished spam/ham cleanup

I do not see my users Junk folder get cleaned every night like the doc says so is this the problem? Reading through the documentation I thought dragging spam to your Junk folder would get it processed overnight?

Running this command trains our filter but it does not remove emails from users Junk folder:
zmtrainsa user@example.com spam Junk