本地服务器邮件发送正常，GoDaddy生产环境SMTP连接被拒绝求助

我的网站表单提交后会向用户发送邮件，该功能在本地服务器运行完全正常，但部署到GoDaddy主机（使用cPanel邮箱）后，出现SMTP连接拒绝错误，怀疑需要在GoDaddy的DNS记录中添加相关配置，但不确定具体操作，恳请帮助。

本地正常运行的代码 #

<?php

$name = $_POST["name"];
$email = $_POST["email"];
$subject = $_POST["subject"];
$message = $_POST["message"];

require "vendor/autoload.php";

use PHPMailer\PHPMailer\PHPMailer;
use PHPMailer\PHPMailer\SMTP;

$mail = new PHPMailer(true);

// $mail->SMTPDebug = SMTP::DEBUG_SERVER;

$mail->isSMTP();
$mail->SMTPAuth = true;

$mail->Host = "back2naturekw.com";
$mail->SMTPSecure = 'None';
$mail->Port = 587;

$mail->Username = "info@back2naturekw.com";
$mail->Password = "***hidden****";

$mail->setFrom('info@back2naturekw.com', 'Back To Nature');
$mail->addAddress($email, $name);

$mail->Subject = $subject;
$mail->Body = $message;

$mail->send();

header("Location: send.php");

部署后出现的错误信息 #

2023-07-02 13:51:53 SMTP ERROR: Failed to connect to server: Connection refused (111)
SMTP Error: Could not connect to SMTP host. Failed to connect to server

Fatal error: Uncaught PHPMailer\PHPMailer\Exception: SMTP Error: Could not connect to SMTP host. Failed to connect to server in /srv/disk5/4339946/www/testersaf.atwebpages.com/vendor/phpmailer/phpmailer/src/PHPMailer.php:2233 Stack trace: #0 /srv/disk5/4339946/www/testersaf.atwebpages.com/vendor/phpmailer/phpmailer/src/PHPMailer.php(2019): PHPMailer\PHPMailer\PHPMailer->smtpConnect(Array) #1 /srv/disk5/4339946/www/testersaf.atwebpages.com/vendor/phpmailer/phpmailer/src/PHPMailer.php(1678): PHPMailer\PHPMailer\PHPMailer->smtpSend('Date: Sun, 2 Ju...', 'final\r\n') #2 /srv/disk5/4339946/www/testersaf.atwebpages.com/vendor/phpmailer/phpmailer/src/PHPMailer.php(1516): PHPMailer\PHPMailer\PHPMailer->postSend() #3 /srv/disk5/4339946/www/testersaf.atwebpages.com/send-email.php(33): PHPMailer\PHPMailer\PHPMailer->send() #4 {main} thrown in /srv/disk5/4339946/www/testersaf.atwebpages.com/vendor/phpmailer/phpmailer/src/PHPMailer.php on line 2233

内容的提问来源于stack exchange，提问作者Muhammad Safnad