<?php
use Microsoft\Graph\GraphServiceClient;
use Microsoft\Graph\Generated\Users\Item\Messages\Item\MessageItemRequestBuilderGetRequestConfiguration;
$graphServiceClient = new GraphServiceClient($tokenRequestContext, $scopes);
$requestConfiguration = new MessageItemRequestBuilderGetRequestConfiguration();
$headers = [
'Prefer' => 'outlook.body-content-type="text"',
];
$requestConfiguration->headers = $headers;
$queryParameters = MessageItemRequestBuilderGetRequestConfiguration::createQueryParameters();
$queryParameters->select = ["subject","body","bodyPreview","uniqueBody"];
$requestConfiguration->queryParameters = $queryParameters;
$result = $graphServiceClient->me()->messages()->byMessageId('message-id')->get($requestConfiguration)->wait();