The 3300 is capable of sending an SNMP trap when an emergency call is made, in fact this is what Mitel's emergency notification apps use as their triggers. So, if you have an SNMP monitor that can send alerts based on the received traps, it should be fairly straightforward to set up, just set the 3300 to send the traps to your SNMP server, and set up the alerts in the server.
Phone-based notifications are restricted to non-hotdesk phones, I don't think softphones are supported.