teste.php

<?php
if (!session_id()) {
	session_start();
}

define('__ROOT__', dirname(__FILE__));

// Importar a classe do PHPMailer
use PHPMailer\PHPMailer\PHPMailer;
use PHPMailer\PHPMailer\Exception;

// Carrega o autoload do composer
require_once __ROOT__.'vendor/autoload.php';

$email = explode(";", $_POST["email"]);

if (!function_exists('email')) {
     /**
     * @param array|string $email
     * @param string $assunto
     * @param string $corpo
     * @param string @replyTo
     * @return boolean
     */
    function email($email = null, $assunto = '(Sem Assunto)', $corpo = null, $replyTo = "retorno@exemplo.com")
    {
        $mail = new PHPMailer(true);   
        try{
            $mail->SMTPDebug        = 2;
            $mail->IsSMTP();
            $mail->Host             = "mail.MEUDOMINIO.com.br";
            $mail->SMTPAuth         = true;
            $mail->Username         = "pedro.ribeiro@MEUDOMINIO.com.br";
            $mail->Password         = 'MINHASENHA';
            $mail->SMTPSecure       = 'tls';
            $mail->Port             = 587;
            /*$mail->SMTPOptions = array(
                'ssl' => array(
                    'verify_peer' => false,
                    'verify_peer_name' => false,
                    'allow_self_signed' => true
                )
            ); */
            $mail->Priority         = 3;
            $mail->Encoding         = 'base64';
            $mail->addCustomHeader('Content-Transfer-Encoding', 'base64');
            $mail->addCustomHeader('MIME-Version', '1.0');
            $mail->SetFrom("naoresponda@exemplo.com", "Meu Nome");
            $mail->AddReplyTo($replyTo, $replyTo);
            $mail->isHTML(true);
            $mail->CharSet          = 'utf-8';
            $mail->Subject          = stripslashes($assunto);
            $mail->Body             = stripslashes($corpo);
            $mail->AltBody          = strip_tags(stripslashes($corpo));
            if (is_array($email)) {
                foreach($email as $addr)
                {
                    $mail->addAddress($addr);
                }
            }
            else {
                $mail->addAddress($email);
            }
            
            $mail->Send();
            return true;
        }
        catch (PHPMailer\PHPMailer\Exception $e) {
            echo 'Mensagem não enviada. Erro: ', $mail->ErrorInfo;
            return false;
        }
    }
}


// ENVIAR EMAIL - TESTAR
$enviar = email($email, "Assunto teste", "corpo aqui");

var_dump($enviar);

header("Location: bilhetes.php");  
die();