I have three mail accounts in thunderbird, and the yahoo (IMAP) account inbox is no longer showing any emails younger than 2006. Some of the yahoo mail folders show emails from 2009 or 2013, but I can no longer see any more recent emails. I have tried repairing the folder, deleting the .msf file, deleting the mail account from thunderbird, restarting thunderbird and/or my computer in between, all to no avail. I had not changed any settings recently; the problem appeared out of nowhere. I have tried everything I read here: http://kb.mozillazine.org/Disappearing_mail What else can I try?