With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
ciscoUnityEventId
cisco Unity Event Id
1.3.6.1.4.1.9.9.385.1.3.4
A number identifying the particular event type. The EventID and EventSource can be used to troubleshoot system problems.
Back to CISCO-UNITY-MIB MIB page.
IPHost Network monitor allows you to monitor ciscoUnityEventId on Cisco device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Cisco firewalls right now.