PHP mail() function doesn't complete sending of e-mail

Question

I need users to send an invitation link to their friends. it works fine before but now I don't know what happened is not working please help. The current PHP version is 8.0 the code works fine but the email will not deliver

<?php
session_start();
require("../include/admin_helper.php");
// global $con;

$invite = mysqli_query($con, "SELECT id, auser FROM admin_v WHERE id = $admin_id ");
$get_inviter = mysqli_fetch_assoc($invite);
$inviter_id = $get_inviter ['id'];
$inviter_user = $get_inviter ['auser'];


if (isset($_POST["signup"])) {
  $full_name = mysqli_real_escape_string($con, $_POST["signup_full_name"]);
  $email = mysqli_real_escape_string($con, $_POST["signup_email"]);
//   $password = mysqli_real_escape_string($con, md5($_POST["signup_password"]));
//   $cpassword = mysqli_real_escape_string($con, md5($_POST["signup_cpassword"]));
  $token = md5(rand());
  $check_email = mysqli_num_rows(mysqli_query($con, "SELECT email FROM members WHERE email='$email'"));
  
   if ($check_email > 0) {
     echo "<script>alert('Your are already sent the invitation');</script>";
   } else {
    $sql = "INSERT INTO members (full_name, email, token, status) VALUES ('$full_name', '$email', '$token', '0')";
    $result = mysqli_query($con, $sql);
    if ($result) {
      $_POST["signup_full_name"] = "";
      $_POST["signup_email"] = "";
      $subject = "Invitation";
      
      $to = $email;

      $message = "
      <html>
      <head>
      <title>{$subject}</title>
      </head>
      <body>
      <p><strong>Welcome {$full_name},</strong></p>
      <p>This is Membership inivitaion! Verify your link to access our website. Click below link to verify your email.</p>
      <p><a href='https://elom.com/login/invite.php?token={$token}&i={$inviter_id}&u={$inviter_user}'>Accept invitation</a></p>
      </body>
      </html>
      ";
      
      $subject="Email invitation - elom.com";
      $body = $message;
      $from_address="invite@".$_SERVER['SERVER_NAME'];
      $from_name="Elom";
      $headers = "MIME-Version: 1.0\r\n"
      ."Content-Type: text/html; charset=utf-8\r\n"
      ."Content-Transfer-Encoding: 8bit\r\n"
      ."From: =?UTF-8?B?". base64_encode($from_name) ."?=<$from_address>\r\n"
      ."X-Mailer: PHP/".phpversion();
       mail($to, $subject, $body, $headers, "-fwebmaster@{$_SERVER['SERVER_NAME']}");
       echo "<script>alert('We have sent a invitation link to your friend email - {$email}.');</script>";
    } else {
      echo "<script>alert('Friend invitation failed.');</script>";
    }
  }
}
//  echo $inviter;
//  echo "hello";
?>

<form method="post" action="">

    <label class="col-lg-2 col-form-label">Full Name</label>
    <div class="col-lg-9">
        <input type="text" class="form-control" name="signup_full_name" required
            value="<?php echo $_POST["signup_full_name"]; ?>"
            placeholder="Full Name">
    </div>

    <label class="col-lg-2 col-form-label">Email</label>
    <div class="col-lg-9">
        <input type="email" class="form-control" name="signup_email" required
            value="<?php echo $_POST["signup_email"]; ?>" placeholder="Email">
    </div>

    <br>
    <div class="col-lg-9">
        <button class="btn btn-primary" name="signup"
            style="margin-left:5px;">invite</button>
    </div>

</form>

I need users to send an invitation link to their friends. it works fine before but now I don't know what happened is not working please help. The current PHP version is 8.0 the code works fine but the email will not deliver

PHP mail() function doesn't complete sending of e-mail

0 Answers0