User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.3a) Gecko/20021212 Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.3a) Gecko/20021212 Happens only at startup, when there is a large batch of incoming mail. Mozilla reports that filters are unable to process mail because another operation is in progress. Mail is put into "basic" inbox without filtering. I operate several different accounts at several ISPs; this usually happens when there is inmail to more than one of them. Mail isn't filtered, so mail to the less-used accounts goes into mailboxes at the bottom of the list, and unless I scroll down (which I rarely do), I miss it. If I'm at the PC, I see the message that Mozilla was unable to filter, and can check. Reproducible: Sometimes Steps to Reproduce: 1. Log off, and don't check e-mail for a day or so. 2. Log on. 3. Usually get the message while the machine is downloading mail. Actual Results: 90% or more of mail filtered correctly. A few items (typically two or three out of 50 or more) put into "other account" inboxes. Expected Results: Filtered mail to "Main" inboxes where there is a detailed table of inmailboxes by subject.

Are you filtering from one account to another? (so it seems from the use of "basic" and "main" inbox wording). Is mail in each account set to auto retrieve mail at some small interval maybe, potentially exacerbating the situation? What kinds of accounts? Are passwords remembered? It may be that your particular filter setup is problematic, don't know. We did implement the "don't filter if folder/mailbox is busy" idea to avoid potential issues with mail message loss when filters were firing. This sounds like it's working in your case.

I posted a reply a week ago - it seems to have disappeared... Yes, I am filtering between accounts. I have 12 separate ones, with several different ISPs. I filter most of the mail to one set of folders. That works OK 99% of the time, but usually gives this error when I first connect to the Net. They are all POP accounts. Passwords are remembered by Mozilla. It could be the "don't filter if busy" feature - that would be consistent. But given that the "busy" state is transient, can it not queue them?

mass re-assign.

*** This bug has been marked as a duplicate of 168648 ***

v.