Yes it is possible.
Create new Probe,
which will be called Voltage,
select Type as SNMP,
put correct OID (which is reporting voltage),
set correct compare method to declare that service is down when value is lower.
Go to the Notification,
create new notification with type e-mail, correct server and correct e-mail
Go to the correct network map and select device, where voltage should be monitored.
Add Voltage service for device monitor,
switch to Notifications and check e-mail notification to use for voltage monitoring.
Thanks sergejs for this simple explanation.