你可以使用SendGrid PHP包来实现这个功能，下面是一个例子来说明你是如何做到的：
在Laravel的注册控制器中：

use SendGrid;
use SendGrid\Mail\To;

class SendGridController extends Controller
{
    public function register(Request $request)
    {
        // ... your rego code
        $apiKey = 'YOUR_API_KEY';
        $sg = new SendGrid($apiKey);

        $list_id = 'YOUR_LIST_ID';

        //Add an email to the list
        $email = new To();
        $email->setEmail($request->input('email'));
        $email->setFirstName($request->input('first_name'));
        $email->setLastName($request->input('last_name'));

        $response = $sg->client->marketing()->lists()->recipients()->post($list_id, $email->jsonSerialize());

        return $response->statusCode();
    }
}

您还可以参考SendGrid API documentation，了解有关如何创建、更新和删除列表以及添加和删除收件人的详细信息。

can be done与sendgrid-php包：

use SendGrid;

$api = new SendGrid(YOUR_API_KEY);
$contacts = [
    [
        'email' => "email@something",
        'address_line_1' => '',
        'city' => '',
        'country' => '',
        'first_name' => '',
        'last_name' => '',
        etc....
    ]
]
$request_body = [
    'contacts' => $contacts
];

$response = $api->client->marketing()->contacts()->put($request_body);
if($response->statusCode() !== 202) {
    // error has occured
}