if another filter moves a message/ deletes a message/Marks a message as junk then that message is no longer present in the inbox for the filters that come after to act on it.

Thanks, Matt. I'm unclear on what you're saying. My filters don't have doubles--no two filters act on the same message or parameters. The problem is that some filters simply don't work. A message stays in my inbox, for instance, when I want to delete it or move it to trash. I'm wondering why such filters don't work at all.

Are you creating the filter on the correct account? That is the most common cause of complaint about filters. They default to Local folders and the account is not local folders.

Thanks, Matt. I've created the filters that don't work in the correct account. That's a good tip, though. I've created new filters from "Create filter from..." in the message addresses, so I'll see how that works.

ajm,

Have you switched any filters between "match any" and "match all"??

ref Bug 1312172 - Changing between "match all of" and "match any of" fails for rules that are not visible. Then filter might fail.