PHP can send email from command line but not browser

I have a form set up at my homepage. When someone submits the form, it redirects them to a php script that sends me the form. The only issue is, the form won't send me anything when I use the browser. I have a script running on the same server that when I execute from the command line, sends an email immediately. When I go to the page in a browser, it gives a confirmation message, but won't send anything. What's happening? PHP is using MSMTP to send email if that helps. I believe apache is running as root (I know that's bad). How do I check?

Here's the code if anyone wants it:

    ini_set( 'display_errors', 1 );

    error_reporting( E_ALL );
    $from = "mailbot@prototypexenon.tech";
    $to = "";
    $subject = "PHP Mail Test script";
    $message = "This is a test to check the PHP Mail functionality";
    $headers = "From:" . $from;
    mail($to,$subject,$message, $headers);
    echo "Test email sent";
?>

EDIT: Apparently new-server-owner was smart enough to not let apache run as root. All fixed now. Thanks @EdHeal

Answer

Apparently new-server-owner was smart enough to not let apache run as root. All fixed now. Thanks @EdHeal