I’m using PHP Mailer for Mail send process. when i use that i have recieving one error message which is
Error:
Admin: Message could not be sent. Mailer Error: SMTP Error: Could not connect to SMTP host. Failed to connect to serverSMTP server error: Failed to connect to server

all data recieving into database when comming to this part: if ($conn) { $stmt = $conn->prepare("INSERT INTO users (name, email) VALUES (?, ?)"); $stmt->bind_param("ss", $name, $email); if (!$stmt->execute()) { echo "Error: Unable to insert data into the database."; exit(); } $stmt->close(); } else { echo "Error: Unable to connect to the database."; exit(); }
But the problem is occuring when send the email for Admin. Give me a solution and let me know what is happening there, and i have set correct all the credentials.

My full code

require '../phpmailer/src/Exception.php';
require '../phpmailer/src/PHPMailer.php';
require '../phpmailer/src/SMTP.php';

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

use PHPMailerPHPMailerPHPMailer;
use PHPMailerPHPMailerException;

if ($_SERVER["REQUEST_METHOD"] == "POST") {
        if (!empty($_POST['username']) && !empty($_POST['email'])) {
            $name = $_POST['username'];
            $mail = $_POST['email'];
            // Save data to the database
            $conn = Connection();
            if ($conn) {
                $stmt = $conn->prepare("INSERT INTO users (name, email) VALUES (?, ?)");
                $stmt->bind_param("ss", $name, $email);
                if (!$stmt->execute()) {
                    echo "Error: Unable to insert data into the database.";
                    exit();
                }
                $stmt->close();
            } else {
                echo "Error: Unable to connect to the database.";
                exit();
            }

            // Send email to admin
            try {
                $mailAdmin = new PHPMailer(true);
                $mailAdmin->isSMTP();
                $mailAdmin->Host = 'smtp.gmail.com';
                $mailAdmin->SMTPAuth = true;
                $mailAdmin->Username = '[email protected]';
                $mailAdmin->Password = 'my authentication key';
                $mailAdmin->SMTPSecure = 'ssl';
                $mailAdmin->Port = 465;

                $mailAdmin->setFrom('[email protected]', 'HIII');
                $mailAdmin->addAddress('[email protected]');
                $mailAdmin->addReplyTo($email, $name);
                $mailAdmin->isHTML(true);
                $mailAdmin->Subject = "New One Arrived";
                $mailAdmin->Body = "A new form submission has been received.<br><br>
                Name: $name<br>Email: $email<br>";

                $mailAdmin->send();
            } catch (Exception $e) {
                echo 'Admin: Message could not be sent. Mailer Error: ', $mailAdmin->ErrorInfo;
                exit();
            }

            // Send thank you email to user
            try {
                $mailUser = new PHPMailer(true);
                $mailUser->isSMTP();
                $mailUser->Host = 'smtp.gmail.com';
                $mailUser->SMTPAuth = true;
                $mailUser->Username = '[email protected]';
                $mailUser->Password = 'my authentication key';
                $mailUser->SMTPSecure = 'ssl';
                $mailUser->Port = 465;

                $mailUser->setFrom('[email protected]', 'HIII');
                $mailUser->addAddress($email);
                $mailUser->isHTML(true);
                $mailUser->Subject = "Thank You for Your Enquiry";
                $mailUser->Body = "Dear $name,<br><br>";

                $mailUser->send();
            } catch (Exception $e) {
                echo 'User: Message could not be sent. Mailer Error: ', $mailUser->ErrorInfo;
                exit();
            }

            // Redirect to dashboard only if both emails are sent successfully
            //if ($adminEmailSent && $userEmailSent) {
            header('Location: dashboard.php');
            exit();
        } else {
            echo 'An error occurred while processing your request.';
        }
    }