If you haven't already considered mbsync as an alternative to OfflineIMAP, I suggest taking a look. I also found OfflineIMAP buggy (many years ago) and mbsync has been syncing my mailboxes reliably since. http://isync.sourceforge.net/ I say this as the author of a program that runs mailbox syncers like mbsync when there are changes to sync (mswatch: http://mswatch.sourceforge.net/).