Twice this year I've lost some archived messages when moving files from an IMAP account to local files on Thunderbird. The problem appears to be that the IMAP server is slow to mark messages, and the "move" then deletes them before moving them. Since I discovered the problem in Feb, I've been careful, but just now went back to July and found some message with just blank headers. 1) Has anyone else seen this? I have a lot of messages, so that could be part of the issue. 2) Any ideas how to ensure the messages are safely moved? I have to delete at some point, and manual checking is quite tedious. JN