I've been noticing apparent duplicate messages within my unified folders inbox on my desktop recently. Looking further I notice that one of my accounts has 'INBOX' as one of its subfolders which is where the problem appears to stem from. When I look at that account in isolation (ie not in unified folders) I can still see the inbox as a subfolder. The subfolder 'INBOX' appears to be a duplicate of the account's main inbox (it contains the same number of emails), which may account for the appearance of duplicates. At a guess this is probably related to inadvertent moving of folders. I find that when trying to use the scroll bar (to scroll down the subfolder list), if the mouse strays slightly to the left it will pick up a subfolder and move it unintentionally. This can cause all sorts of problems with disappearing emails and the folder structures showing differently on different computers. In this case the duplicate email problem only happens on my desktop. On my laptop I can still see a subfolder named 'INBOX' but it shows as empty and I don't see the duplicate emails in unified folders. It would be really useful if Mozilla could introduce a 'confirm folder move' feature as that would eradicate inadvertent moves. How do I resolve the apparent duplicate emails on my desktop? I am somewhat reticent to delete the subfolder 'INBOX' for fear of the potential consequences. . .