获取PHP致命错误：未捕获的错误：smtp电子邮件脚本中的类'SendGrid \ Email'

Question

嗨，我正在尝试使用php和sendgrid从我的网站发送电子邮件。这是我的php：

<?php

require_once('sendgrid-php/sendgrid-php.php');

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

try {
    $from = new SendGrid\Email(null, $email);
    $subject = $header;
    $to = new SendGrid\Email(null, "MY EMAIL");
    $content = new SendGrid\Content("text/plain", $message);
    $mail = new SendGrid\Mail($from, $subject, $to, $content);

    $apiKey = 'MY API KEY';
    $sg = new \SendGrid($apiKey);

    $response = $sg->client->mail()->send()->post($mail);
    if($response->statusCode() == 202){
         echo "Email sent successfully";
    } else {
         echo "Email could not be sent";
    }
} catch (Exception $e) {
    echo $e->errorMessage();
} 

echo $response->statusCode();
var_dump($response->headers());
echo $response->body(); 

我收到此错误； PHP致命错误：未捕获错误：在/home/al8xghxhnuw5/public_html/scripts/index.php:11

中找不到类'SendGrid \ Email'

我四处寻找修复程序，但没有任何效果，添加了require sendgrid-php / lib // mail / Email.php无效。

我整天都在努力工作，任何帮助都会很棒