[OS:N:] Messaging system & support

[Robert Citek <rwcitek alum calberkeley org>]

Hello all,

I got this message from a friend.

On Thursday, Aug 12, 2004, at 10:06 US/Central, [a friend] wrote:
> I'm managing a project here at [some company] to replace our email 
> system from the current unix-based sendmail/smtp/pop3 setup with 
> Eudora clients to something else--whatever that turns out to be.  We 
> have people demanding built-in calendaring and while they could use 
> Outlook as a client with our current server offerings, the calendaring 
> won't be as nice as if we had an Exchange Server behind it.
>
> I have no problem finding people to install and support Exchange, but 
> I'm trying to present alternatives as well.  The leader seems to be 
> SuSE Linux's Openexchange Server (now owned by Novell).  But I don't 
> know who could support us on that locally.
>
> Do you know of any companies that could give us really good support on 
> whatever system we choose, even up to 24/7/365 if we want to pay for 
> that?

Any ideas?  Specifically:
 - What other products offer built-in (or nearly built-in) Calendaring?
 - Any opinions on SLOX?
 - Is there any reason not to use Exchange?
 - What other questions should my friend be asking?

Regards,
- Robert