propose to put 
[Submit] [Back] [Submit & Notify] button on top/bottom

new parameter 'shell option' 

[test]
...
Attributes = NotifyMode, Param1....Param10, Adresse, Subject, ...
Options NotifyMode = mail, SMS, Fax, printer...

; this command will invoque a shell command  
; example       
ShellCommand = <my shell command> parameters ...

like in WINDOWS 2000
ShellCommand = START.EXE notify.bat $NotifyMode $Param1, $Param2, $Param3
; in this case no necessity to modify the C source
; in windows I suggest the start.exe with a exit command
; so no necessary to wait the return code from the shell