We have changed from MS server to Linux clearOS based one,
and instead of Exchange we have Zarafa - all good, except on the mail
side. Simply, we want what Exchange can give - a server hosted mailbox
that gets synchronised to client machine so on client side you get off-line
access, but work done on your client machine in off-line mode then gets updated
to server once connected, or other way round; if you use 3[sup]rd[/sup] party
machine and access your email from web, then when next connected, your local
copy mirrors what you did on the server.