I need a Unix-based tool, such as a shell script or command-line program, to copy IMAP folders from one server to another. Ideally, the tool should copy all the folders for a single account (Inbox, Sent, Trash, and user-created folders) at once, rather than one folder at a time. It should preserve message dates. As an option, I'd like to be able to copy just a single IMAP folder.
Alternatively, is there a tool to copy an mbox file to an IMAP server? I have direct access to the mbox files in the filesystem, but not to the filesystem of the remote IMAP server.
Edit: Is there a way for a user to migrate their own questions to Server Fault?