I'm trying to provide some conceptual assistance to an Outlook
user.  I myself haven't used OL for several years, so I'm a little
uncertain about what functions these days are performed by OL and
what functions are performed by an Exchange server, if there is
one.  I'll post the question here, and I'd appreciate any
information.  If this is the wrong newsgroup, please point me to
the correct one.

A friend has OL on her desktop, her laptop, an auxiliary desktop,
and on her assistant's desktop.  None of these are networked,
although the desktops are on the 'net and the laptop occasionally
hooks in to the 'net.  The only OL installations actually being
used are the assistant's site and--maybe, not sure about this--my
friend's primary desktop.  (I assume, though I'm not really sure,
that they have sufficient site licenses for all of this.)  They
would like to network the OL installations so that they synch.

Can this be done without an Exchange server, similar, e.g., to the
way that Notes can synch by e-mail without a Domino server?  What
are the options for doing what they want?