There's too much hostility flying around here. We're all on the same side and all trying to find an answer!
I'm not convinced that ANY of the problem here is Apple's fault, nor am I convinced it isn't. Apple Mail isn't connecting, but neither is Entourage 2008 Web Services Edition. BOTH will connect through IMAP, of course, but that's not the goal.
While my office definitely has Exchange Server 2007 with Roll-Up 9, there's a chance (who knows, except for the IT staff?) that they didn't install the (apparently) optional "Exchange Web Services" module, which is a separate download from Microsoft for Exchange Server 2007. Does anyone know if there is a way that a regular domain user can see if it's been installed?
Also, I found the following:
Update Rollup 4 for Exchange Server 2007 Service Pack 1
(KB952580) should also be applied to both the Mailbox
server and the Client Access server roles.
So, if they applied the Service Pack and Roll-Ups to the Mailbox server, maybe they didn't apply them to the Client Access server. I can't say.
It seems like either one of these issues could stop Mail (or Entourage EWS) from working, and they're completely beyond control of the average user to fix in a corporate email system.
Thanks to this forum, however, I learned that Exchange support on the iPhone is handled a totally different way. I appreciate that understanding.
I've sent a lot of this information to my IT guys to see if they will (hopefully) say, "Oh, yeah, we never installed Exchange Web Services." We'll see.
Good luck, all. Hopefully we're edging closer to an answer for us!