PHP Contact Form on my page doesn't send emails

I am hosting my website here and when I try to use a contact form to send an email I don’t receive the email. I tested it with the email account hosted here and with my yahoo email but it doesn’t work. At the same time, I can send and receive emails between my yahoo email and the email hosted here. I’m sure the php script is ok, but why I can’t send email?

Well, a recommendation for sending emails is PHPMailer. It’s an open source program that sends emails using a SMTP. If you have SMTP support with your plan, then you can use your website as the “from domain”… but otherwise, use something like GMail. Link: GitHub - PHPMailer/PHPMailer: The classic email sending library for PHP

Have you checked the FAQ article about PHP mail? The answer is in it:

I am not sure if the free plan supports SMTP.

@intlaqa said:
I am not sure if the free plan supports SMTP.

We don’t operate an SMTP service for free hosting users, but you can connect to an external SMTP server.