I am using a pre-email filter called Spam Weasel to try to identify junk mail. What it does is get control first on email retrieves, runs through its rules and affixes a keyword (SPAM) to the front of subject. I then have a rule in Outlook that forces anything with SPAM in the subject to a junk folder. It's a really simple rule that simply says that when a message arrives with SPAM in the subject field, move it to the JUNK folder.
Intermittenly, I will get a message like this in its own message box:
SPAM Cannot remove messages from the folder.
When this happens, the rule gets turned off and the junk goes into my Inbox folder. I have not been able to discover what causes the rule to fail or why Outlook would turn off a rule on its own. Any ideas?