I am using Thunderbird for a gmail account and it appears to have suddenly broken at about 9am (UK time) today. There are two issues which seem to be related: 1. If I copy or move e-mails from a different account into this account it claims to be copying or moving them, but they do not appear. 2. The most recent sent message sometimes gets duplicated into the inbox (when I get messages), and sometimes into the folder I'm copying or moving into instead of the message I'd like. It's a duplicate in the sense that when I delete one of the multiple copies, all of them go. The problem is restricted to this gmail account: I have another one on the same thunderbird profile which is fine, as well as two others on other machines. I have already deleted and reset the gmail account on Thunderbird, so I suspect the problem may be at the gmail end. I was on 45.3.0 when the problem started: it has since upgraded to 45.4.0. Any ideas what I could try? Thanks, Colin Bell