We can get into situations where we have an offline imap move/copy operation to a folder that doesn't exist. Since we do all move/copy operations pseudo offline, this can affect non-offline users as well. E.g., rogue code :-) like the patch in bug 451995 can do this. Whatever the cause, the problem is that we will keep retrying the move/copy every time the source folder is selected, and it will never succeed. It also prevents us from getting new mail for that folder. The patch makes us drop the move/copy offline operations if the dest folder doesn't exist. This will make us stop retrying. Once the offline ops are dropped, we will redownload the headers for the affected messages. This situation should really not happen in normal circumstances, so I've made it an assertion.

Comment on attachment 353446 [details] [diff] [review] proposed fix >+ nsCOMPtr <nsIMsgImapMailFolder> imapFolder = do_QueryInterface(m_currentFolder); >+ if (imapFolder && DestFolderOnSameServer(destFolder)) nit: not your fault, but please drop the space from between the nsCOMPtr and the <

fix checked in.