With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
ccmVMailDevStatus
Cisco Call Manager V Mail Device Status
1.3.6.1.4.1.9.9.156.1.12.1.1.5
The status of the Voice Messaging Device. The Voice Messaging Device status changes from unknown to registered when it registers itself with the local CUCM.
Back to CISCO-CCM-MIB MIB page.
IPHost Network monitor allows you to monitor ccmVMailDevStatus on Cisco device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Cisco optical switches right now.