How to test macro: sc_mail_send()

I have found few lines of code in the Macro help like this:

if ({sc_mail_ok}){
    echo "Message sent successfuly";
}else{
    echo "Message failed !";
}

These lines added after the sc_mail_send() macro supposed to test if the Email was send successfully.
is sc_mail_OK() another undocumented macro or what is it ?
As usually macro help SUCKS !

Could anybody englighten me how this internally works ?
What values the {sc_mail_ok} field supposed to get and where from ?

My App is sending Emails, but I would like to post some confirmation on the screen.

This seems to be part of the work sc_mail_send is doing.
Similar to the status of phpmailer or the …_erro variable returned by sc_select().

I found the following documentation helpful:

The amount of emails sent will be stored at the special variable “sc_mail_count”.

If any error happend when the scriptcase try to send the email, the variable “sc_mail_ok” will recieve “false” and the error message will be stored on the variavle “sc_mail_erro”.

Ex.4 :
sc_mail_send([glo_smtp], ‘’, ‘’, ‘from@netmake.com.br’, {to}, {subject}, {message}, ‘H’);

if ({sc_mail_ok})
{
echo “sent {sc_mail_count} e-mail(s) with sucess!!”;
}
else
{
sc_error_message({sc_mail_erro});
}

Sincerely

Gunter Eibl
Scriptcase.Coach

Yes, I tested in local Variable and it takes value of 0 OR 1. I do not understand why it is not even documented.