UM does not have a dedicated log for email and snmp. You can check in the ocie log folder for server.log, and in the ocum log folder for ocumserver.log, you may see failures there if it is not successful.
Otherwise, you can configure an alert with an option to send a snmp trap as well, and test the alert.
Or collect a packet trace if you expect an alert to be triggered that would send a trap.
If this is not an OVA deployment of UM, you could also install an snmp tool and test SNMP from UM to the traphost.
Sending UM OID ocumAlertTest from a RHEL server with net-snmp-utils installed:
[root@dawnr-um ~]# snmptrap -c public -v2c 10.216.25.47 trapoid .1.3.6.1.4.1.789.5.1.0.11111
Received:
For the OVA and Linux deployments, you can try using 'nc' with the UDP switch.
How to check connectivity to SNMP destinations in Active IQ Unified Manager
Log locations:
What are the notable log files and their respective locations for Active IQ Unified Manager?