this line:
$WA_MailObject = WA_SecurityAssist_Definition("yourmailserver.yourdomain.com","25","","","");
should be:
$WA_MailObject = WA_SecurityAssist_Definition("yourmailserver.yourdomain.com","25","","","","");
to set the email body, edit the Email Password behavior, and go the Email Settings tab. in the Message section, you set the email body.