You can integrate CUCM and Exchange to have UM. You need to configure a SIP trunk between these two servers. On the CUCM side, you can configure a SIP trunk as described on the following document:
-> Trunk Configuration
On the Exchange side, you need to refer to MS: --> Microsoft Exchange 2010 Unified Messaging PBX Configuration Note for Cisco Unified Communications Manager 7.0
Attached are some screenshots on how to configure this on the Exchange.
Tere Stevens ----- Unified Communications PDI Teamwww.cisco.com/go/pdihelpdesk