Edit: The future is here! I’ve shortened my wishlist since OfflineIMAP now supports the IDLE command.
Further Edit: Kerberos instructions for Mac OS now available
For some time I’ve been meaning to make use of some sort of mail caching, in order to use my favourite email client whilst offline. The end result of this process is that my incoming mail now takes a somewhat circuitous route of:
imap server | offlineimap - local uw-imapd - alpine | local cache
on my laptop.