sendgrid_test.php

<?php
// using SendGrid's PHP Library
// https://github.com/sendgrid/sendgrid-php
// If you are using Composer (recommended)
require 'vendor/autoload.php';
// If you are not using Composer
// require("path/to/sendgrid-php/sendgrid-php.php");
$apiKey = getenv('SENDGRID_APIKEY');
$sg = new \SendGrid($apiKey);

$request_body = json_decode('{
  "from": {
    "email": "[email protected]", 
    "name": "こだわりん"
  },
  "personalizations": [
    {
      "bcc": [
        {
          "email": "[email protected]", 
          "name": "こだわりん"
        }
      ],
	  "to": [
        {
          "email": "'."[email protected]".'", 
          "name": "森鷗外"
        }
      ]
	}
  ],
  "categories": [
    "customer_register", 
    "transaction"
  ], 
  "reply_to": {
    "email": "[email protected]", 
    "name": "こだわりん"
  },
  "template_id": "8b0e3576-xxxx-xxxx-91ec-bf3dff4d16ec"
}');


$response = $sg->client->mail()->send()->post($request_body);
dump($response->statusCode());
dump($response->body());
dump($response->headers());