yes-with some work (see style 3 below)
Alright, you got a bunch of different methods here...let me give you a list of all the options/possibilities at once.
They're separated into styles with some point values based on the functionality/ease of a particular action.
Style 1: Compliance 3 - Search 3 - Restore 1 = 7pts. in favor
Automatic forking can better be equated with
'easily search-able compliance archives'.
-
ZAD to the same zcs server, another zcs server, (either way you can make use of HSM) or another simple mail server tied to some storage
-always_bcc in postifx to some other account/mailserver (it's the OS concept of zad; but with a lot more organizational work needed on your end setting up filters to sort the user's mail into folders, etc
/forums/administrators/8659-enhancement-hacks-power-filters.html)
-you can technically use these as backups in a pinch, but only for messages
Style 2: Compliance 2 - Search 1 - Restore 3 = 6pts. in favor
While you can do restoreToTimes with the backups, for the most part it takes on the '
ability to restore in case something goes wrong' definition.
Here we got the original: Just save the installer files with the backups, and when needed setup a quick temp box to restore to. (Move the backups around rsync/scp etc to wherever you wish; hard drives, tape, optical disk, etc)
But, The reason I suggested the automatic methods in the first place was because of the ease of search, I guess your first decision is zimbra's index & search capabilities, your filesystem's, or a thick-client's search?
Because it sounds like you are thinking that hopefully you won't need to go get these 5 year old emails on a regular basis but you still want them 'compliance like' & search-able.
Style 3: Compliance 1 Search 1 Restore 1 = 3pts. in favor
'
snapshot status of their mailboxes' definition - These methods are even more manual & won't have all the actions they took + you could be missing mail that they've deleted between snapshot times.
-set up imapsync cron jobs to some cheaper mailserver box
-rsync copies of the store
-REST & CURL (export/imports)
-ie zip'ed .eml archives; when you want to view them import them into a thick-client OR convet .eml > .msg & use zmlmtpinject or zmmailbox addMessge to put the messages back into zimbra
-for calendars you export in .ics...reimport with curl, etc