Why wp_mail() function isn't sending any emails and displaying '0' in Chrome 'Network' response

I'm trying to send emails through wordpress using wp_mail() function and it doesn't seem to work.

It's displaying 0 in Chrome 'Network' response with

Status Code:200 OK

this my code part:

// Contact form  Ajax 

add_action('wp_ajax_nopriv_submit_contact_form', 'submit_contact_form'); 

function submit_contact_form(){

    if(isset($_POST['email'])) {

        $email = $_POST['email'];       
        $email_to = "info@company.com";

        $host = "ssl://smtp.gmail.com:465";
        $username = 'myEmail@company.pro';
        $password = 'passpass';

        $email_subject = "You have a new email from $email via company.com website";
        $message = $_POST['text']; 

        $headers = array ('From' => $email, 'To' => $email_to,'Subject' => $email_subject);
        /*$smtp = Mail::factory('smtp',
          array ('host' => $host,
            'auth' => true,
            'username' => $username,
            'password' => $password));*/

        //$mail = $smtp->send($email_to, $headers, $message);

        wp_mail( $email_to, $email_subject, $message );

        /*if (PEAR::isError($mail)) {
          echo($mail->getMessage());
        } else {
          echo("Message successfully sent!\n");
        }*/
    }
}





error_reporting(E_ALL);
ini_set("display_errors", 1);

What part might be wrong?