可以'；t提交后，请将此联系PHP表格发送到我的电子邮件中

我正在尝试创建一个php联系人表单，以便在提交后发送到我的电子邮件中。

注意：

-我只想从这个联系表格中收到我的电子邮件的电话号码和信息；然而，我无法做到这一点。

-表单提交后，我想显示一条感谢信息。我收到了一条找不到页面的消息。

-我希望表单安全，不受黑客攻击。

-我还想将电话字段验证为仅数字。

如有任何帮助，我们将不胜感激。

<?php
// define variables and set to empty values
$nameErr = $emailErr = $phoneErr = "";
$name = $email = $comment = $phone = "";
$to = 'myemail@gmail.com';
$subject = $_POST['Phone'];
$message = $_POST['comment'];
if ($_SERVER["REQUEST_METHOD"] == "POST") {
  if (empty($_POST["name"])) {
    $nameErr = "Name is required";
  } else {
    $name = test_input($_POST["name"]);
    // check if name only contains letters and whitespace
    if (!preg_match("/^[a-zA-Z ]*$/",$name)) {
      $nameErr = "Only letters and white space allowed"; 
    }
  }
  if (empty($_POST["email"])) {
    $emailErr = "Email is required";
  } else {
    $email = test_input($_POST["email"]);
    // check if e-mail address is well-formed
    if (!filter_var($email, FILTER_VALIDATE_EMAIL)) {
      $emailErr = "Invalid email format"; 
    }
  }
  if (empty($_POST["phone"])) {
    $phoneErr = "Phone is required";
  } else {
    $phone = test_input($_POST["phone"]);
  }

  if (empty($_POST["comment"])) {
    $comment = "";
  } else {
    $comment = test_input($_POST["comment"]);
  }
  //if "email" variable is filled out, send email
  if (isset($_POST['Submit']))  {
  //send email
  mail($to, $subject, $message);
  //Email response
  echo "Thank you for contacting us!";
  }
}

function test_input($data) {
  $data = trim($data);
  $data = stripslashes($data);
  $data = htmlspecialchars($data);
  return $data;
}
?>

<h2>PHP Form</h2>
<form method="post" action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]);?>">  
  <input type="text" name="name" placeholder="Name">
  <span class="error">* <?php echo $nameErr;?></span>
  <br><br>
  <input type="text" name="email" placeholder="E-mail">
  <span class="error">* <?php echo $emailErr;?></span>
  <br><br>
  <input type="text" name="website" placeholder="Phone">
  <span class="error"><?php echo $websiteErr;?></span>
  <br><br>
  <textarea name="comment" placeholder="Concerns?"></textarea>
  <br><br>
  <input type="submit" name="submit" value="Submit">
</form>