Exchange servers and IMAP, any reason to have it off?

Is there any good reasons for having IMAP off on an Exchange server? I'm switching to the Mac at my work, and mail is the last issue. I have Entourage working via the webdav mail server they have, but it has some problems. Specifically, any message sent to me with "..." in the subject is inaccessible. Trying it via the actual webmail interface (OWA) results in a 404, due to the server using URLs with the subject in them. (Side rant, I find it amusing that an expensive web mail client provided with Exchange server can't read all the mail a user might have, but yet something free like SquirrelMail has no problems).

The best solution would be to use IMAP over WebDAV to access the mail, also opening the door to use the OS X Mail app. I'm really wanting to kick Entourage to the curb for lacking such basic features as "Customize Toolbar". The problem is, the server admin says "there are several reasons for IMAP being disabled" but doesn't provide a reason why. Beyond the additional overhead of running the IMAP service, is there any issues that would crop up on an Exchange server with it on? It seemed to work fine at HP, never saw any problems, and never had complaints from IT when I used it.

I have never seen any problems with it, other than the fact that it seems to not like to restart on reboot. Other than that, it (obviously) doesn't support Exchange-specific stuff, like calendaring, voting via email, etc.

On the other hand, I don't have a problem with Outlook Web Access and emails whose subjects contain either three contiguous periods or ellipses.

Quote:
it seems to not like to restart on reboot.

If there wasn't a solution to that one, that'd definitely make me delete it from my servers. Wow.

I'm surprised about the Exchange Webmail thing where it can't read all of its own mail. There's probably a KB article on that one if you hunted for it.