FPD Form doesn't send an email. Just show: The order could not be sent. Please try again or contact the site owner!
Is there some thing (configuration) I must do before it is work?
Please update to FPD version 3.4.2, it should fix the problem. If it does not for some reason please do open a support ticket with some login credentials and a link to your wp-admin and we'll fix it for you.