SMTP: CLIENT: 535 5.7.3 Authentication Unsuccessful - php

Question

I'm trying to send an email every time someone inputs a form on my website but the SMTP isn't working. It keeps on showing me this error. The credentials of the email account are correct. Also, I have already tried SMTPAuth = False; but still the same result.
<?php
$name = $_POST['name'];
$email = $_POST['email'];
$message = $_POST['message'];
// 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;
//Load Composer's autoloader
require 'vendor/autoload.php';
$mail = new PHPMailer(true);
try {
//Server settings
$mail->SMTPDebug = 2;
$mail->isSMTP();
$mail->Host = 'smtp.office365.com';
$mail->Port = 587;
$mail->SMTPSecure = 'TLS';
$mail->SMTPAuth = true;
$mail->Username = 'sender#test.com'; // SMTP username
$mail->Password = 'password'; // SMTP password
//Recipients
$mail->setFrom('test#test.com', ' Services');
$mail->addAddress('recipient#test.com', $name); // Add a recipient
//Content
$mail->isHTML(true); // Set email format to HTML
$mail->Subject = 'Contact Us Message';
$mail->Body = 'Sent a message, This is the message :';
$mail->AltBody = 'This is the body in plain text for non-HTML mail clients';
$mail->send();
header('Location: tempage.php');
} catch (Exception $e) {
echo 'Message could not be sent. Mailer Error: ', $mail->ErrorInfo;
}
?>
What is going wrong? Thanks for your help.

Answer 1

I'm also struggling 2 days with same issue.
After i find this solution. It's working fine.
Try this.
$mail->Host = 'smtp.office365.com';
change to
$mail->Host = 'smtp.live.com';