If you wish to send emails successfully via our Hosted Demos Platform you will need to utilise a 3rd party plugin that enables you to create a connection to your own email SMTP server to send emails from your own domain.
When you receive access to your hosted demo platform, the popular WP Mail SMTP plugin will be installed. You can choose whether or not to enable this on your primary site and configure it to be able to send emails via your account. Or you can remove it and install your preferred SMTP Mail plugin instead. Some good options can be found here.