Barny,

There are a host of approaches to this, and in the end your budget for
this will likely determine what you go with.

The most ambitious goal is to have totally redundant services; eg a
second server with Win2K3 and Exchange licensed, patched, and
configured as a domain controller. Obviously, this is not justifiable
for smaller networks.

Second to that, you can aim for fault tolerance on the workstation end.
Run your Outlook 2003 in cached mode. Use your web host for their
secondary MX services if your Exch runs as a front-end server, then
configure a POP3/SMTP account in each OL client to use the ISP for
outgoing e-mails and the web host for incoming. Just keep that account
inactive in the Send/Receive part until your outage occurs. You could
even plan an outage in order to test this. Instead of (or in addition
to) backing up to tape, have a network computer whose storage capacity
matches that of your existing file shares, and back up nightly to that
instead.

So, you could potentially survive an outage on the server with minimal
impact to the end-users. If you have other services on the server, then
you need to get more creative, but you get the idea. If you want to go
over these in detail, feel free to contact me;
justin@synergyassured.com

Cheers.
netjustin