Geographically Redundant mail stores

[Michael Fair]

Greetings all,

I'm doing some work on how to create a somewhat
reliable geographically redundant mail system.

The idea is that site A would be the primary site.
The MX record would point to a machine at that
site and everything would work as normal.

Then there'd be a site B.  The backup site if you
will.  It is in a physically different place with
a different IP address and the MX records point
to this site as a backup.

Mail would be delivered to either one or the other
mail store and synchronized regularly.

Mailsync would run every 15 minutes to an hour
depending upon performance (it's a small site 15 users).

My question was that the only user I know that
can see the whole tree is an admin user.  But
by default admin users can't select the mailboxes
because they don't have the proper permissions.

Could this be done?  Is it a viable solution?
I like the 3-way diff that mailsync uses (works
great for individual mailbox hierarchies) but
having to manage the configuration for each user
would be a major chore.


If easily granting an admin user rights on the whole
tree is hard or not a good idea (I'd create a separate
user just for this purpose) then can 'unison' be used
to update the directory trees.  For those that don't
know unison is essentially a 2-way rsync with different
conflict resolution options.

Any other ideas on this topic would be appreciated.

-- Michael --