php mailer wont send mail to rest of email addresses after it got any bad email in between

Question

I wrote a PHP mailer code to send emails to multiple recipients. But unfortunately i found a drawback in script, i am fetching emails from database, lets see if it fetches 5 emails and try to send email to all of them and no.3 email is not a valid address(any reason) then my script just "exist" the function entirely by sending mail to 1-2 and showing error invalid email 3 and "exit"(not continuing further), what i want is rather to "exit" the function it should just skip that iteration statement(email) and then go on to next one like the "continue" statement. Also in code the message and subject are being sent from another page which consists of a form. Here is the code :

<?php
// Import PHPMailer classes into the global namespace
// These must be at the top of your script, not inside a function
use PHPMailer\PHPMailer\PHPMailer;
use PHPMailer\PHPMailer\Exception;
if(isset($_SESSION['userIs']))
{
$message = $_POST['message'];
$subject = $_POST['subject'];
//Load composer's autoloader
require './PHPMailer/vendor/autoload.php';
$mail = new PHPMailer(true);                              // Passing `true` enables exceptions
try {
    //Server settings
    $mail->SMTPDebug = 1;                                 // Enable verbose debug output
    $mail->isSMTP();                                      // Set mailer to use SMTP
    $mail->Host = 'smtp.gmail.com';  // Specify main and backup SMTP servers
    $mail->SMTPAuth = true;                               // Enable SMTP authentication
    $mail->Username = 'trying.test.00';                 // SMTP username
    $mail->Password = 'trying.test.00';                           // SMTP password
    $mail->SMTPSecure = 'tls';                            // Enable TLS encryption, `ssl` also accepted
    $mail->Port = 587;                                    // TCP port to connect to
    //Recipients
    $mail->setFrom('trying.test.00@gmail.com', 'Tester');
include('./create-connection.php');
$get_list = "select name,email from signup";
$result = $conn->query($get_list) ;
if($result->num_rows>0)
{
    while($row_list = $result->fetch_assoc())
    {
        $to = $row_list['email'];
        $name = $row_list['name'];
        $mail->addAddress($to,$name);     // Add a recipient    
    }
}
    //Content
    $mail->isHTML(true);                                  // Set email format to HTML
    $mail->Subject = $subject;
    $mail->Body    = $message;
    $mail->AltBody = strip_tags($message);
    if($mail->send())
    {
    echo '<div class=""><b>'.$to.'</b> -> Status <i class="fa fa-check"></i></div>';
    }
} catch (Exception $e) {
echo '<div class=""><b>'.$to.'</b> -> Status <i class="fa fa-times"></i></div>';   
}
$conn->close();
}
?>

Answer 1

Just needed to add a validation to check if the email is valid or not without sending email inside while loop, then if email is valid process the mail else "continue" the current iteration(email) and jump to next email. Thus after changing code ->

  <?php
    // Import PHPMailer classes into the global namespace
    // These must be at the top of your script, not inside a function
    use PHPMailer\PHPMailer\PHPMailer;
    use PHPMailer\PHPMailer\Exception;
    if(isset($_SESSION['userIs']))
    {
    $message = $_POST['message'];
    $subject = $_POST['subject'];
    //Load composer's autoloader
    require './PHPMailer/vendor/autoload.php';
    $mail = new PHPMailer(true);                              // Passing `true` enables exceptions
    try {
        //Server settings
        $mail->SMTPDebug = 1;                                 // Enable verbose debug output
        $mail->isSMTP();                                      // Set mailer to use SMTP
        $mail->Host = 'smtp.gmail.com';  // Specify main and backup SMTP servers
        $mail->SMTPAuth = true;                               // Enable SMTP authentication
        $mail->Username = 'trying.test.00';                 // SMTP username
        $mail->Password = 'trying.test.00';                           // SMTP password
        $mail->SMTPSecure = 'tls';                            // Enable TLS encryption, `ssl` also accepted
        $mail->Port = 587;                                    // TCP port to connect to
        //Recipients
        $mail->setFrom('trying.test.00@gmail.com', 'Tester');
    include('./create-connection.php');
    $get_list = "select name,email from signup";
    $result = $conn->query($get_list) ;
    if($result->num_rows>0)
    {
        while($row_list = $result->fetch_assoc())
        {
    //add a validation here 

    if(!filter_var($row_list['email'], FILTER_VALIDATE_EMAIL))
            {
                echo "invalid email".$row_list['email'];
            continue;   
            }
       else
       {
           $to = $row_list['email'];
            $name = $row_list['name'];

            $mail->addAddress($to,$name);     // Add a recipient
        }
        }
    }
        //Content
        $mail->isHTML(true);                                  // Set email format to HTML
        $mail->Subject = $subject;
        $mail->Body    = $message;
        $mail->AltBody = strip_tags($message);
        if($mail->send())
        {
        echo '<div class=""><b>'.$to.'</b> -> Status <i class="fa fa-check"></i></div>';
        }
    } catch (Exception $e) {
    echo '<div class=""><b>'.$to.'</b> -> Status <i class="fa fa-times"></i></div>';   
    }
    $conn->close();
    }
    ?>

Answer 2

You could validate the email addresses before sending.

Or better:

You could validate the email addresses before inserting in the database so you know that the database contains only valid data.