HiJan,
You don't have email feature but SNMP Monitoring can be setup for each device:
My Wan- Devices - {device} - configure - Monitoring - Snmp - General
Settings
The 'WAE:' section will alert for any disk failure and 'WAE Alarm:' will alert for any class of alarm. You cannot set for a specific alarm. Maybe you can do this on the SNMP Manager which receives the trap.
For more details please visit:
http://www.cisco.com/en/US/docs/app_ntwk_services/waas/waas/v521/configuration/guide/SNMP.html#wp1099613
Regards,
Kanwal