I'm still banging away at this problem and haven't yet found a satisfactory solution.
There is a lot of mail hosted on my company's web hosting service, it's kept in a Cyrus IMAP server and access is via Horde/Imp webmail. This works pretty well but I'd like to be able to get at it in other ways and to archive some of it.
So I asked the sysadmin to open up the IMAP server so I can access it from my home machine, this he has done and I can access it via IMAP/SSL on port 993. Using an stunnel client I can also access it as an 'ordinary' IMAP server for clients that don't do SSL.
My two main requirements are:-
1 - To be able to copy (large) IMAP folders containing old sentmail as archived by Horde to our home machines, it can then be backed up there (saved to CD for instance) and removed from the Cyrus server to save space.
2 - To be able to copy a complete hierarchy of a user's messages on the IMAP server to a home machine. This will enable access with a normal (as opposed to webmail) client, I may even move some users from the remote webmail service to a home machine.
I can find no utility or mail client that does both of the above satisfactorily. Initially one would think that any MUA that handles IMAP mail should be able to do it but I can't find one that does. Even the simpler requirement 1 can't be handled by most mail clients, e.g.:- Thunderbird - if you drag and drop a folder from the IMAP server to a local folder the folder is copied but none of its contents are copied, they do however appear to be removed from the remote folder - instant loss of mail!
OE (yes someone recommended this) - simply can't be made to move/copy folders as far as I can see.
I've tried Balsa and Kmail but neither worked, I can't remember the exact details.
mutt - does a reasonable job, you can tag all the mail messages in an IMAP folder and then copy them to a local folder. However it's a bit clumsy and isn't really dealing with folders.
Moving a whole hierarchy is even more difficult because each MUA and IMAP server seems to have its own way of arranging things, some see INBOX as the root of a user's hierarchy, others see INBOX as just another folder rooted at the same place as the rest of the hierarchy. Some allow both folders and mail in a folder, some don't. Often the view of a remote IMAP server is different from a local hierarchy.
There are a number of utilities (imapsync, iisync, imapcopy, offlineimap, etc.) which are supposed to copy IMAP hierarchies but none works for me yet.
A while ago I *did* successfully copy some IMAP hiearachies from a UW-Imap server to my home system but the same utility doesn't work satifactorily running from a Cyrus server. One of the main problems is that Cyrus allows both folders and mail within a folder, this needs some workarounds when transferring to a server (or mailbox hierarchy) where this isn't possible.
Does anyone have any suggestions (apart from writing my own utility in perl, which is where I seem to be going at the moment).