Hello all. Two weeks ago I posted this problem under a different head, but got no replies, so let me try again as it is messing up maybe 5% of my email. Every morning I collect email--from 40 to 70 messages, many forwarded from Gmail--and message filtering usually works efficiently to transfer from Inbox to folders. But somewhere along the line, 1 to 3 emails get muddled together: the from and/or subject don't match the text, and sometimes the displayed text includes the Msg Source, including text, from some other, unrelated email. I've been using FF and TB for more than 10 years now, and believe this kind of email muddling dates only to the last couple months. I use the latest Thunderbird under Windows 7 on a Dell desktop. I have 4 hopefully innocent addons. Of course I can send screenshots and forward the message source for analysis. Hoping this time to attract attention to the problem! Thanks!