I have two email accounts I read with Thunderbird. A few days ago one of them was suddenly missing a huge number of emails, but not all of them. The other account still works fine in Thunderbird. Both are Yahoo! accounts, and I can view all the email messages for both accounts on Yahoo! mail just fine. I have tried rebuilding the .msf file for the problematic account, but that didn't help. I haven't set up any filters or done anything to change my account settings in a very long time. I'm using: Windows 7 Thunderbird 31.7.0