My client is interested in setting up email archival in such a way that user mail older than a certain date (say, 30 days) is stored locally on the mail server and viewable/accessible via the Zimbra web GUI, but is NOT viewable/accessible via an IMAP account on a desktop mail client.

I originally suggested HSM, but they don't like the idea that mail is still viewable from the desktop client even when it's stored on the HSM drive.

We're running ZCS Version 6.0.14_GA_2928.NETWORK.