The Gmail (fc.mm.mp.lh is Gmail also) accounts that I've set up with Mail, automatically created a second folder for each of the accounts, the ones you can see in ALL CAPS at the bottom.

I guess this folders represent the web mail accounts, while the folders inside Inbox represent the pop accounts, despite them being the same account. The thing is, as you can see, while the inbox accounts have no unread mails, their "all caps" counterparts show as if they had some unread mails.

This is not the normal behavior; when I mark an email as read, it is "read" in both versions of the account, but from time to time, they kind of get "out of sync" and the bottom folders start to show unread emails that were actually read. Have you seen this behavior before? What can I do?

I don't use the bottom "folders" but I can't get rid of them anyway. It's just that their unread messages notification annoys me because there aren't actually any unread mails.