My office manager has now been running Thunderbird for several years, after migrating from Outlook and then moving from an XP computer to a Windows 7 computer. She noticed last week that there were several copied mail folders. I finally got a chance to look at it this week; it seems that the problem has been ongoing for some time before she reported it. She has not been backing up her profile at all. As I recall it, when we went to ditch Outlook it wasn't easy to go straight from Outlook to Thunderbird, so we migrated first to Outlook Express. Then in migrating to Thunderbird the existing folder structure came in as 'Outlook Express Import,' separate from the Inbox. Under 'Outlook Express Import' she has a folder named 'Correspondence Files,' containing a subfolder for each client, and has been moving the mail for each client from the Inbox to the respective subfolders in Correspondence Files. Checking out her Thunderbird now: -The original 'Correspondence Files' folder under 'Outlook Express Import' seems to be fine; but -There is also now an Inbox/'Correspondence Files' folder that has copies of each client subfolder up to I, along with a an Inbox/'Correspondence Files(2)' file that has copies of each subfolder up through I; and -Inbox/'Correspondence Files' has separate subfolders 'Correspondence Files (2)' (copies of each client subfolder through K) and 'Correspondence Files (2)(2)' (copies of each client subfolder through C). So as far as I can see, at least four copies of at least some of the basic 'Correspondence Files' folder were produced either by her inadvertently or by some glitch within Thunderbird. 1) My main question is how we can prevent this from happening in the future. Any advice about how it may have happened in the first place would also be welcome since that would aid us in the goal of having it happen again. 2) My secondary question stems from the fact that while she (thankfully) largely stuck to the original Correspondence Files subfolders for her email filing, she did have a few inconsistencies in the filing - so a few emails may have been filed in one of the copied subfolders by accident. As far as I can tell the divergence in some cases goes back about two months. So - I'm thinking this is a long shot, but is there a way we can somehow merge the disparate versions of the client subfolders (w/o copying and pasting the entire contents of each, since I suspect that would create redundant copies of emails that exist in both subfolders)? Or does she have to go through each copy of each subfolder independently? (Which is not desirable, but not impossible.) 3) Once we've made sure that as little of the correspondence has slipped through the cracks as possible, can we just go about deleting the copied Correspondence Files folders? Right click delete? Or do I need to do something more complex? Thanks, Dan