Apple Mail doesn't apply rules unless I choose "Apply Rules" manually

I found following post: http://www.cnet.com/how-to/how-to-delete-and-manage-old-messages-in-os-x-mail/

So you have to do the following:

1. Add your filter that you want to apply.
2. Add the rule condition: Every message.
3. Set the drop down to "all"

You need to set "all" because if you set "any". What happens is that it evaluates every message, it will automatically match "every message". Then because you set "any". It won't consider the actual filter. Then it'll execute the action. So if you set the "delete" action. You will automatically delete every message in your inbox. A very dangerous mistake.

This is a bug.

In their infinite wisdom, Mail.app developers decided only to apply rules to 'unseen' messages. If the IMAP 'seen' flag is set, rules will not be applied.

I started a forum thread on the apple forums on this topic.

I had the same issue, but it turned out the first rule in the list (News from Apple) had "Stop evaluating rules" as the last action.

I removed this action and it worked fine.