Several of our customers use internal Microsoft Exchange servers to host their email accounts, with an mx record pointing to them in our zone file.
On most of these accounts, I have noticed that the Exchange servers are requesting zone transfers for the email domain(s) they manage. Here is an example log entry:
Apr 11 05:43:51 admin named[25801]: client ip.address.of.exchange#34963: update 'domain.org/IN' denied
Obviously this is some default setting within Exchange. Any idea what purposes these requests serve, and how to shut them off on the Exchange side?
Thanks for the help.

Erek Dyskant