sendContato.php

<?php
require_once 'autoload.php';

$content = trim(file_get_contents("php://input"));
$decoded = json_decode($content, true);

extract($decoded);

$empresa = new \conteudoSite\Empresa();

$mail = new \SendGrid\Mail\Mail();
$mail->setFrom($email, $nome);
$mail->setReplyTo($email, $nome);
$mail->setSubject("Formulário de Contato - " . $empresa->getNome());
$mail->addTo($empresa->getEmail(), $empresa->getNome());
$mail->setTemplateId('4413a27b-3bac-497c-bec4-8d6b1aad205b');

$sendgrid = new \SendGrid('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');

$body = "<p><strong>Nome:</strong> $nome</p>";
$body .= "<p><strong>E-mail:</strong> $email</p>";
$body .= "<p><strong>Telefone:</strong> <a href='tel:$telefone'>$telefone</a></p>";
$body .= "<p><strong>Mensagem:</strong> $mensagem</p>";

$mail->addContent("text/html", $body);

$response['success'] = false;

try {
    $response = $sendgrid->send($mail);

    if($response->statusCode() == 200) {
        $response['success'] = true;
    }
} catch (Exception $e) {
    http_response_code(500);
    $response['message'] = $e->getMessage();
}

echo json_encode($response);