PHPMailer not posting to email

[BenHoward]

So I am trying to use PHP mailer on my site however it doesn't post to the email

Here is the code:

Top:

   <?php 

    use PHPMailer\PHPMailer\PHPMailer;
    use PHPMailer\PHPMailer\Exception;

    require 'vendor/phpmailer/phpmailer/src/Exception.php';
    require 'vendor/phpmailer/phpmailer/src/PHPMailer.php';
    require 'vendor/phpmailer/phpmailer/src/SMTP.php';
   ?>

Where it sends:

            require 'vendor/autoload.php';

            //Instantiation and passing `true` enables exceptions
            $mail = new PHPMailer(true);
            
            try {
                //Server settings
                $mail->SMTPDebug = SMTP::DEBUG_SERVER;                      //Enable verbose debug output
                $mail->isSMTP();                                            //Send using SMTP
                $mail->Host       = 'smtp.office365.com';                     //Set the SMTP server to send through
                $mail->SMTPAuth   = true;                                   //Enable SMTP authentication
                $mail->Username   = 'maileremail';                     //SMTP username
                $mail->Password   = 'mailerpassword';                               //SMTP password
                $mail->SMTPSecure = PHPMailer::ENCRYPTION_STARTTLS;         //Enable TLS encryption; `PHPMailer::ENCRYPTION_SMTPS` encouraged
                $mail->Port       = 587;                                    //TCP port to connect to, use 465 for `PHPMailer::ENCRYPTION_SMTPS` above
            
                //Recipients
                $mail->setFrom('maileremail', 'Mailer');
                $mail->addAddress(myemail', 'Joe User');     //Add a recipient
            
                //Content
                $mail->isHTML(true);                                  //Set email format to HTML
                $mail->Subject = 'Here is the subject';
                $mail->Body    = 'This is the HTML message body <b>in bold!</b>';
                $mail->AltBody = 'This is the body in plain text for non-HTML mail clients';
            
                $mail->send();
                echo 'Message has been sent';
            } catch (Exception $e) {
                echo "Message could not be sent. Mailer Error: {$mail->ErrorInfo}";
            }
                  ?>

I have tried everything but it still won't post.
 

[requinix]

"Won't post" isn't a particularly helpful description.

What have you done to troubleshoot this yourself so far? Checked for error messages? Spam folders? Tried using different email accounts, both for sending as well as receiving?