For the security of our customers, we do not permit unauthenticated outbound mail via the PHP mail() function. This is to prevent spam emails being sent from our servers, which could lead to the blacklisting of our IP addresses, affecting the outbound emails of other customers. To send emails from your site, you'll have to use SMTP, whether it be via a plugin, like WordPress's WP Mail SMTP or similar. If you have any questions or require assistance with this, don't hesitate to reach out to us.