Define what mailbox means to you.  If you are talking about the calendar and
other little goodies including public folders, none do that except maybe
CommVault.  And, I do not think they can do the public folders.

The thing that Veritas and Arcserver created are for marketing only and
really are so slow you can only use it for a few select mailboxes.

None replace the normal exchange backups that you have to do to be able to
recover the exchange stores.

I found out just yesterday that Exchange 2000 has a reserved area you can
restore an information store to.  Once you have done that you can truly
recover a mailbox and its contents.  This was Microsoft's answer to the
problem.  But, Exchange 2000 requires active directory and other hurdles to
get there.  However, my Exchange boys point out you must not put any
mailboxes you might want to recover in the "base" information store because
that one cannot be restored to the reserve area.  That one has all the
exchange specific extensions to active directory.

Paul D. Seay, Jr.
Technical Specialist
Naptheon, INC
757-688-8180