IMAP as it stands does not seem to cater at all well for shared folders.
The Cyrus server has no problem at all with shared folders. CMU uses shared folders heavily (hundreds, if not thousands of folders) with clients ranging from Pine to Mulberry to Outlook to Mozilla.
What is needed is not to try to shift the burden to the servers but force the clients to get their act together.
In my 5-6 years of experience with IMAP, this statement is completely contrary to what the IMAPEXT WG has been trying to do. The burden has always been placed on the server in an effort to keep clients as lightweight as possible. FWIW, I agree with the stance that the server should do the heavy lifting.
-- Kenneth Murchison Oceana Matrix Ltd. Software Engineer 21 Princeton Place 716-662-8973 x26 Orchard Park, NY 14127 --PGP Public Key-- http://www.oceana.com/~ken/ksm.pgp