Everytime you see a 'Mail' Alert available as action it triggers the action defined in 'Run mail alert script'.
'User Alert' triggers 'Run UserDefined script no.1'.
'User Alert 2 ' triggers 'Run UserDefined script no.2'.
'User Alert 3' triggers 'Run UserDefined script no.3'.
You need to adjust your current default settings to meet your actual requirements and environment for mail server, sender and reciepent email address. I provided you with some examples in my last reply.
The 'Send mail alert to SmartView Monitor' option is described in Check Points integrated Help as shown below.